/*
% Copyright (C) 2003, 2004 GraphicsMagick Group
% Copyright (C) 2002 ImageMagick Studio
% Copyright 1991-1999 E. I. du Pont de Nemours and Company
%
% This program is covered by multiple licenses, which are described in
% Copyright.txt. You should have received a copy of Copyright.txt with this
% package; otherwise see http://www.graphicsmagick.org/www/Copyright.html.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                            PPPP   N   N   GGGG                              %
%                            P   P  NN  N  G                                  %
%                            PPPP   N N N  G  GG                              %
%                            P      N  NN  G   G                              %
%                            P      N   N   GGG                               %
%                                                                             %
%                                                                             %
%             Read/Write Portable Network Graphics Image Format.              %
%                                                                             %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                           Glenn Randers-Pehrson                             %
%                               November 1997                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/* GraphicsMagick differences */
#define LoadImageTag LoadImageText
#define SaveImageTag SaveImageText
#define LoadImagesTag LoadImagesText
#define SaveImagesTag SaveImagesText
#define ParseMetaGeometry GetMagickGeometry
#define AcquireUniqueFilename AcquireTemporaryFileName
#define LiberateUniqueFileResource LiberateTemporaryFile
#define first_scene subimage
#define number_scenes subrange

#if !defined(RGBColorMatchExact)
#define RGBColorMatchExact(color,target) \
   (((color).red == (target).red) && \
    ((color).green == (target).green) && \
    ((color).blue == (target).blue))
#endif

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/attribute.h"
#include "magick/blob.h"
#include "magick/cache.h"
#include "magick/color.h"
#include "magick/constitute.h"
#include "magick/enhance.h"
#include "magick/log.h"
#include "magick/magick.h"
#include "magick/monitor.h"
#include "magick/quantize.h"
#include "magick/static.h"
#include "magick/semaphore.h"
#include "magick/tempfile.h"
#include "magick/transform.h"
#include "magick/utility.h"
#if defined(HasPNG)
#include "png.h"
#include "zlib.h"

#if PNG_LIBPNG_VER > 95
/*
  Optional declarations. Define or undefine them as you like.
*/
/* #define PNG_DEBUG -- turning this on breaks VisualC compiling */

/*
  Features under construction.  Define these to work on them.
*/
#undef MNG_OBJECT_BUFFERS
#undef MNG_BASI_SUPPORTED
#define MNG_COALESCE_LAYERS /* In 5.4.4, this interfered with MMAP'ed files. */
#define MNG_INSERT_LAYERS   /* Troublesome, but seem to work as of 5.4.4 */
#define PNG_BUILD_PALETTE   /* This works as of 5.4.3. */
#define PNG_SORT_PALETTE    /* This works as of 5.4.0. */
#if defined(HasJPEG)
#  define JNG_SUPPORTED /* Not finished as of 5.5.2.  See "To do" comments. */
#endif

/*
  Establish thread safety.
  setjmp/longjmp is claimed to be safe on these platforms:
  setjmp/longjmp is alleged to be unsafe on these platforms:
*/
#ifndef SETJMP_IS_THREAD_SAFE
#define PNG_SETJMP_NOT_THREAD_SAFE
#endif

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
static SemaphoreInfo
  *png_semaphore = (SemaphoreInfo *) NULL;
#endif

/*
  This is temporary until I set up malloc'ed object attributes array.
  Recompile with MNG_MAX_OBJECTS=65536L to avoid this limit but
  waste more memory.
*/
#define MNG_MAX_OBJECTS 256

/*
  If this is not defined, spec is interpreted strictly.  If it is
  defined, an attempt will be made to recover from some errors,
  including
      o global PLTE too short
*/
#undef MNG_LOOSE

/*
  Don't try to define PNG_MNG_FEATURES_SUPPORTED here.  Make sure
  it's defined in libpng/pngconf.h, version 1.0.9 or later.  It won't work
  with earlier versions of libpng.  From libpng-1.0.3a to libpng-1.0.8,
  PNG_READ|WRITE_EMPTY_PLTE were used but those have been deprecated in
  libpng in favor of PNG_MNG_FEATURES_SUPPORTED, so we set them here.
  PNG_MNG_FEATURES_SUPPORTED is disabled by default in libpng-1.0.9 and
  will be enabled by default in libpng-1.2.0.
*/
#if (PNG_LIBPNG_VER == 10009)  /* work around libpng-1.0.9 bug */
#  undef PNG_READ_EMPTY_PLTE_SUPPORTED
#  undef PNG_WRITE_EMPTY_PLTE_SUPPORTED
#endif
#ifdef PNG_MNG_FEATURES_SUPPORTED
#  ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
#    define PNG_READ_EMPTY_PLTE_SUPPORTED
#  endif
#  ifndef PNG_WRITE_EMPTY_PLTE_SUPPORTED
#    define PNG_WRITE_EMPTY_PLTE_SUPPORTED
#  endif
#endif

/*
  Maximum valid unsigned long in PNG/MNG chunks is (2^31)-1
  This macro is only defined in libpng-1.0.3a and later.
*/
#ifndef PNG_MAX_UINT
#define PNG_MAX_UINT (png_uint_32) 0x7fffffffL
#endif

/*
  Constant strings for known chunk types.  If you need to add a chunk,
  add a string holding the name here.   To make the code more
  portable, we use ASCII numbers like this, not characters.
*/

static png_byte FARDATA mng_MHDR[5]={ 77,  72,  68,  82, '\0'};
static png_byte FARDATA mng_BACK[5]={ 66,  65,  67,  75, '\0'};
static png_byte FARDATA mng_BASI[5]={ 66,  65,  83,  73, '\0'};
static png_byte FARDATA mng_CLIP[5]={ 67,  76,  73,  80, '\0'};
static png_byte FARDATA mng_CLON[5]={ 67,  76,  79,  78, '\0'};
static png_byte FARDATA mng_DEFI[5]={ 68,  69,  70,  73, '\0'};
static png_byte FARDATA mng_DHDR[5]={ 68,  72,  68,  82, '\0'};
static png_byte FARDATA mng_DISC[5]={ 68,  73,  83,  67, '\0'};
static png_byte FARDATA mng_ENDL[5]={ 69,  78,  68,  76, '\0'};
static png_byte FARDATA mng_FRAM[5]={ 70,  82,  65,  77, '\0'};
static png_byte FARDATA mng_IEND[5]={ 73,  69,  78,  68, '\0'};
static png_byte FARDATA mng_IHDR[5]={ 73,  72,  68,  82, '\0'};
static png_byte FARDATA mng_JHDR[5]={ 74,  72,  68,  82, '\0'};
static png_byte FARDATA mng_LOOP[5]={ 76,  79,  79,  80, '\0'};
static png_byte FARDATA mng_MAGN[5]={ 77,  65,  71,  78, '\0'};
static png_byte FARDATA mng_MEND[5]={ 77,  69,  78,  68, '\0'};
static png_byte FARDATA mng_MOVE[5]={ 77,  79,  86,  69, '\0'};
static png_byte FARDATA mng_PAST[5]={ 80,  65,  83,  84, '\0'};
static png_byte FARDATA mng_PLTE[5]={ 80,  76,  84,  69, '\0'};
static png_byte FARDATA mng_SAVE[5]={ 83,  65,  86,  69, '\0'};
static png_byte FARDATA mng_SEEK[5]={ 83,  69,  69,  75, '\0'};
static png_byte FARDATA mng_SHOW[5]={ 83,  72,  79,  87, '\0'};
static png_byte FARDATA mng_TERM[5]={ 84,  69,  82,  77, '\0'};
static png_byte FARDATA mng_bKGD[5]={ 98,  75,  71,  68, '\0'};
static png_byte FARDATA mng_cHRM[5]={ 99,  72,  82,  77, '\0'};
static png_byte FARDATA mng_gAMA[5]={103,  65,  77,  65, '\0'};
static png_byte FARDATA mng_iCCP[5]={105,  67,  67,  80, '\0'};
static png_byte FARDATA mng_pHYg[5]={112,  72,  89, 103, '\0'};
static png_byte FARDATA mng_pHYs[5]={112,  72,  89, 115, '\0'};
static png_byte FARDATA mng_sBIT[5]={115,  66,  73,  84, '\0'};
static png_byte FARDATA mng_sRGB[5]={115,  82,  71,  66, '\0'};
static png_byte FARDATA mng_tRNS[5]={116,  82,  78,  83, '\0'};

#if defined(JNG_SUPPORTED)
static png_byte FARDATA mng_IDAT[5]={ 73,  68,  65,  84, '\0'};
static png_byte FARDATA mng_JDAT[5]={ 74,  68,  65,  84, '\0'};
static png_byte FARDATA mng_JDAA[5]={ 74,  68,  65,  65, '\0'};
static png_byte FARDATA mng_JdAA[5]={ 74, 100,  65,  65, '\0'};
static png_byte FARDATA mng_JSEP[5]={ 74,  83,  69,  80, '\0'};
static png_byte FARDATA mng_oFFs[5]={111,  70,  70, 115, '\0'};
#endif

/*
static png_byte FARDATA mng_hIST[5]={104,  73,  83,  84, '\0'};
static png_byte FARDATA mng_iCCP[5]={105,  67,  67,  80, '\0'};
static png_byte FARDATA mng_iTXt[5]={105,  84,  88, 116, '\0'};
static png_byte FARDATA mng_sPLT[5]={115,  80,  76,  84, '\0'};
static png_byte FARDATA mng_tEXt[5]={116,  69,  88, 116, '\0'};
static png_byte FARDATA mng_tIME[5]={116,  73,  77,  69, '\0'};
static png_byte FARDATA mng_zTXt[5]={122,  84,  88, 116, '\0'};
*/

typedef struct _MngBox
{
  long
    left,
    right,
    top,
    bottom;
} MngBox;

typedef struct _MngPair
{
  volatile long
    a,
    b;
} MngPair;

#ifdef MNG_OBJECT_BUFFERS
typedef struct _MngBuffer
{

  unsigned long
    height,
    width;

  Image
    *image;

  png_color
    plte[256];

  int
    reference_count;

  unsigned char
    alpha_sample_depth,
    compression_method,
    color_type,
    concrete,
    filter_method,
    frozen,
    image_type,
    interlace_method,
    pixel_sample_depth,
    plte_length,
    sample_depth,
    viewable;
} MngBuffer;
#endif

typedef struct _MngInfo
{

#ifdef MNG_OBJECT_BUFFERS
  MngBuffer
    *ob[MNG_MAX_OBJECTS];
#endif

  Image *
    image;

  RectangleInfo
    page;

  int
    adjoin,
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
    bytes_in_read_buffer,
    found_empty_plte,
#endif
    equal_backgrounds,
    equal_chrms,
    equal_gammas,
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    equal_palettes,
#endif
    equal_physs,
    equal_srgbs,
    framing_mode,
    have_global_bkgd,
    have_global_chrm,
    have_global_gama,
    have_global_phys,
    have_global_sbit,
    have_global_srgb,
    have_saved_bkgd_index,
    have_write_global_chrm,
    have_write_global_gama,
    have_write_global_plte,
    have_write_global_srgb,
    need_fram,
    object_id,
    old_framing_mode,
    optimize,
    saved_bkgd_index;

  int
    new_number_colors;

  long
    image_found,
    loop_count[256],
    loop_iteration[256],
    scenes_found,
    x_off[MNG_MAX_OBJECTS],
    y_off[MNG_MAX_OBJECTS];

  MngBox
    clip,
    frame,
    image_box,
    object_clip[MNG_MAX_OBJECTS];

  unsigned char
    /* These flags could be combined into one byte */
    exists[MNG_MAX_OBJECTS],
    frozen[MNG_MAX_OBJECTS],
    loop_active[256],
    invisible[MNG_MAX_OBJECTS],
    viewable[MNG_MAX_OBJECTS];

  ExtendedSignedIntegralType
    loop_jump[256];

  png_colorp
    global_plte;

  png_color_8
    global_sbit;

  png_byte
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
    read_buffer[8],
#endif
    global_trns[256];

  float
    global_gamma;

  ChromaticityInfo
    global_chrm;

  RenderingIntent
    global_srgb_intent;

  unsigned long
    delay,
    global_plte_length,
    global_trns_length,
    global_x_pixels_per_unit,
    global_y_pixels_per_unit,
    mng_width,
    mng_height,
    ticks_per_second;

  unsigned int
    IsPalette,
    global_phys_unit_type,
    basi_warning,
    clon_warning,
    dhdr_warning,
    jhdr_warning,
    magn_warning,
    past_warning,
    phyg_warning,
    phys_warning,
    sbit_warning,
    show_warning,
    mng_type,
    write_mng,
    write_png8,
    write_png24,
    write_png32;

#ifdef MNG_BASI_SUPPORTED
  unsigned long
    basi_width,
    basi_height;

  unsigned int
    basi_depth,
    basi_color_type,
    basi_compression_method,
    basi_filter_type,
    basi_interlace_method,
    basi_red,
    basi_green,
    basi_blue,
    basi_alpha,
    basi_viewable;
#endif

  png_uint_16
    magn_first,
    magn_last,
    magn_mb,
    magn_ml,
    magn_mr,
    magn_mt,
    magn_mx,
    magn_my,
    magn_methx,
    magn_methy;

  PixelPacket
    mng_global_bkgd;

} MngInfo;
#endif /* VER */

/*
  Forward declarations.
*/
static unsigned int
  WritePNGImage(const ImageInfo *,Image *);
static unsigned int
  WriteMNGImage(const ImageInfo *,Image *);
#if defined(JNG_SUPPORTED)
static unsigned int
  WriteJNGImage(const ImageInfo *,Image *);
#endif

#if PNG_LIBPNG_VER > 95
#if defined(PNG_SORT_PALETTE)
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   C o m p r e s s C o l o r m a p T r a n s F i r s t                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method CompressColormapTransFirst compresses an image colormap removing
%  any duplicate and unused color entries and putting the transparent colors
%  first.
%
%  The format of the CompressColormapTransFirst method is:
%
%      unsigned int CompressColormapTransFirst(Image *image)
%
%  A description of each parameter follows:
%
%    o image: The address of a structure of type Image.
%
%
*/
static unsigned int CompressColormapTransFirst(Image *image)
{
  int
    remap_needed,
    k;

  long
    j,
    new_number_colors,
    number_colors,
    y;

  PixelPacket
    *colormap;

  register const PixelPacket
    *p;

  register IndexPacket
    *indexes,
    top_used;

  register long
    i,
    x;

  IndexPacket
    *map,
    *opacity;

  unsigned char
    *marker,
    have_transparency;

  /*
    Determine if colormap can be compressed.
  */
  assert(image != (Image *) NULL);
  if (image->storage_class != PseudoClass || image->colors > 256 ||
      image->colors < 2)
    return(False);
  marker=MagickAllocateMemory(unsigned char *,image->colors);
  if (marker == (unsigned char *) NULL)
    ThrowBinaryException(ResourceLimitError,MemoryAllocationFailed,
      "Unable to compress image colormap")
  opacity=MagickAllocateMemory(IndexPacket *,
    image->colors*sizeof(IndexPacket));
  if (opacity == (IndexPacket *) NULL)
    {
      MagickFreeMemory(marker);
      ThrowBinaryException(ResourceLimitError,MemoryAllocationFailed,
        "Unable to compress image colormap")
    }
  /*
    Mark colors that are present.
  */
  number_colors=(long) image->colors;
  for (i=0; i < number_colors; i++)
  {
    marker[i]=False;
    opacity[i]=OpaqueOpacity;
  }
  top_used=0;
  for (y=0; y < (long) image->rows; y++)
  {
    p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
    if (p == (const PixelPacket *) NULL)
      break;
    indexes=GetIndexes(image);
    if (image->matte)
      for (x=0; x < (long) image->columns; x++)
      {
        marker[(int) indexes[x]]=True;
        opacity[(int) indexes[x]]=p->opacity;
        if (indexes[x] > top_used)
           top_used=indexes[x];
        p++;
      }
    else
      for (x=0; x < (long) image->columns; x++)
      {
        marker[(int) indexes[x]]=True;
        if (indexes[x] > top_used)
           top_used=indexes[x];
      }
  }

  if (image->matte)
  {
    /*
      Mark background color, topmost occurrence if more than one.
    */
    for (i=number_colors-1; i; i--)
    {
      if (RGBColorMatchExact(image->colormap[i],image->background_color))
        {
          marker[i]=True;
          break;
        }
    }
  }
  /*
    Unmark duplicates.
  */
  for (i=0; i < number_colors-1; i++)
    if (marker[i])
      {
        for (j=i+1; j < number_colors; j++)
          if ((opacity[i] == opacity[j]) &&
              (RGBColorMatchExact(image->colormap[i],image->colormap[j])))
            marker[j]=False;
       }
  /*
    Count colors that still remain.
  */
  have_transparency=False;
  new_number_colors=0;
  for (i=0; i < number_colors; i++)
    if (marker[i])
      {
        new_number_colors++;
        if (opacity[i] != OpaqueOpacity)
          have_transparency=True;
      }
  if ((!have_transparency || (marker[0] && (opacity[0] == TransparentOpacity)))
      && (new_number_colors == number_colors))
    {
      /*
        No duplicate or unused entries, and transparency-swap not needed
      */
      MagickFreeMemory(marker);
      MagickFreeMemory(opacity);
      return(True);
    }

  remap_needed=False;
  if ((long) top_used >= new_number_colors)
     remap_needed=True;

  /*
    Compress colormap.
  */

  colormap=MagickAllocateMemory(PixelPacket *,image->colors*sizeof(PixelPacket));
  if (colormap == (PixelPacket *) NULL)
    {
      MagickFreeMemory(marker);
      MagickFreeMemory(opacity);
      ThrowBinaryException(ResourceLimitError,MemoryAllocationFailed,
        "Unable to compress image colormap")
    }
  /*
    Eliminate unused colormap entries.
  */
  map=MagickAllocateMemory(IndexPacket *,number_colors*sizeof(IndexPacket));
  if (map == (IndexPacket *) NULL)
    {
      MagickFreeMemory(marker);
      MagickFreeMemory(opacity);
      MagickFreeMemory(colormap);
      ThrowBinaryException(ResourceLimitError,MemoryAllocationFailed,
        "Unable to compress image colormap")
    }
  k=0;
  for (i=0; i < number_colors; i++)
  {
    map[i]=(IndexPacket) k;
    if (marker[i])
      {
        for (j=i+1; j < number_colors; j++)
        {
          if ((opacity[i] == opacity[j]) &&
              (RGBColorMatchExact(image->colormap[i],image->colormap[j])))
            {
               map[j]=(IndexPacket) k;
               marker[j]=False;
            }
        }
        k++;
      }
  }
  j=0;
  for (i=0; i < number_colors; i++)
  {
    if (marker[i])
      {
        colormap[j]=image->colormap[i];
        j++;
      }
  }
  if (have_transparency && (opacity[0] != TransparentOpacity))
    {
      /*
        Move the first transparent color to palette entry 0.
      */
      for (i=1; i < number_colors; i++)
      {
        if (marker[i] && opacity[i] == TransparentOpacity)
          {
            PixelPacket
              temp_colormap;

            temp_colormap=colormap[0];
            colormap[0]=colormap[(int) map[i]];
            colormap[map[i]]=temp_colormap;
            for (j=0; j < number_colors; j++)
            {
              if (map[j] == 0)
                map[j]=map[i];
              else if (map[j] == map[i])
                map[j]=0;
            }
            remap_needed=True;
            break;
          }
      }
   }

  MagickFreeMemory(opacity);
  MagickFreeMemory(marker);

  if (remap_needed)
    {
      /*
      Remap pixels.
      */
      for (y=0; y < (long) image->rows; y++)
      {
        p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
        if (p == (const PixelPacket *) NULL)
          break;
        indexes=GetIndexes(image);
        for (x=0; x < (long) image->columns; x++)
        {
          j=(int) indexes[x];
          indexes[x]=map[j];
        }
        if (!SyncImagePixels(image))
          break;
      }
      for (i=0; i < new_number_colors; i++)
         image->colormap[i]=colormap[i];
    }
  MagickFreeMemory(colormap);
  image->colors=new_number_colors;
  MagickFreeMemory(map);
  return(True);
}
#endif

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I m a g e I s G r a y                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%   Like IsGrayImage except does not change DirectClass to PseudoClass        %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*/
static unsigned int ImageIsGray(Image *image)
{
  register const PixelPacket
    *p;

  register long
    i,
    x,
    y;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);

  if (image->storage_class == PseudoClass)
    {
      for (i=0; i < (long) image->colors; i++)
        if (!IsGray(image->colormap[i]))
          return(False);
      return(True);
    }
  for (y=0; y < (long) image->rows; y++)
  {
    p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
    if (p == (const PixelPacket *) NULL)
      return(False);
    for (x=(long) image->columns; x > 0; x--)
    {
       if (!IsGray(*p))
          return(False);
       p++;
    }
  }
  return(True);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I m a g e I s M o n o c h r o m e                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%   Like IsMonochromeImage except does not change DirectClass to PseudoClass  %
%   and is more accurate.                                                     %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*/
static unsigned int ImageIsMonochrome(Image *image)
{
  register const PixelPacket
    *p;

  register long
    i,
    x,
    y;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);

  if (image->storage_class == PseudoClass)
    {
      for (i=0; i < (long) image->colors; i++)
      {
        if (!IsGray(image->colormap[i]) || ((image->colormap[i].red != 0)
            && (image->colormap[i].red != MaxRGB)))
          return(False);
      }
      return(True);
    }
  for (y=0; y < (long) image->rows; y++)
  {
    p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
    if (p == (const PixelPacket *) NULL)
      return(False);
    for (x=(long) image->columns; x > 0; x--)
    {
      if ((p->red != 0) && (p->red != MaxRGB))
        return(False);
      if (!IsGray(*p))
        return(False);
      p++;
    }
  }
  return(True);
}
#endif /* PNG_LIBPNG_VER > 95 */
#endif /* HasPNG */

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s M N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method IsMNG returns True if the image format type, identified by the
%  magick string, is MNG.
%
%  The format of the IsMNG method is:
%
%      unsigned int IsMNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o status:  Method IsMNG returns True if the image format type is MNG.
%
%    o magick: This string is generally the first few bytes of an image file
%      or blob.
%
%    o length: Specifies the length of the magick string.
%
%
*/
static unsigned int IsMNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(False);
  if (memcmp(magick,"\212MNG\r\n\032\n",8) == 0)
    return(True);
  return(False);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s J N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method IsJNG returns True if the image format type, identified by the
%  magick string, is JNG.
%
%  The format of the IsJNG method is:
%
%      unsigned int IsJNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o status:  Method IsJNG returns True if the image format type is JNG.
%
%    o magick: This string is generally the first few bytes of an image file
%      or blob.
%
%    o length: Specifies the length of the magick string.
%
%
*/
static unsigned int IsJNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(False);
  if (memcmp(magick,"\213JNG\r\n\032\n",8) == 0)
    return(True);
  return(False);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s P N G                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method IsPNG returns True if the image format type, identified by the
%  magick string, is PNG.
%
%  The format of the IsPNG method is:
%
%      unsigned int IsPNG(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o status:  Method IsPNG returns True if the image format type is PNG.
%
%    o magick: This string is generally the first few bytes of an image file
%      or blob.
%
%    o length: Specifies the length of the magick string.
%
%
*/
static unsigned int IsPNG(const unsigned char *magick,const size_t length)
{
  if (length < 8)
    return(False);
  if (memcmp(magick,"\211PNG\r\n\032\n",8) == 0)
    return(True);
  return(False);
}

#if defined(HasPNG)
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#if (PNG_LIBPNG_VER > 95)
static size_t WriteBlobMSBULong(Image *image,const unsigned long value)
{
  unsigned char
    buffer[4];

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  buffer[0]=(unsigned char) (value >> 24);
  buffer[1]=(unsigned char) (value >> 16);
  buffer[2]=(unsigned char) (value >> 8);
  buffer[3]=(unsigned char) value;
  return(WriteBlob(image,4,buffer));
}

static void PNGLong(png_bytep p,png_uint_32 value)
{
  *p++=(png_byte) ((value >> 24) & 0xff);
  *p++=(png_byte) ((value >> 16) & 0xff);
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}

static void PNGsLong(png_bytep p,png_int_32 value)
{
  *p++=(png_byte) ((value >> 24) & 0xff);
  *p++=(png_byte) ((value >> 16) & 0xff);
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}

static void PNGShort(png_bytep p,png_uint_16 value)
{
  *p++=(png_byte) ((value >> 8) & 0xff);
  *p++=(png_byte) (value & 0xff);
}

static void PNGType(png_bytep p,png_bytep type)
{
  (void) memcpy(p,type,4*sizeof(png_byte));
}

static void LogPNGChunk(int logging, png_bytep type, unsigned long length)
{
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Writing %c%c%c%c chunk, length: %lu",
        type[0],type[1],type[2],type[3],length);
}
#endif /* PNG_LIBPNG_VER > 95 */

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#if PNG_LIBPNG_VER > 95
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d P N G I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method ReadPNGImage reads a Portable Network Graphics (PNG) or
%  Multiple-image Network Graphics (MNG) image file and returns it.  It
%  allocates the memory necessary for the new Image structure and returns a
%  pointer to the new image or set of images.
%
%  MNG support written by Glenn Randers-Pehrson, randeg@alum.rpi.edu.
%
%  The format of the ReadPNGImage method is:
%
%      Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image:  Method ReadPNGImage returns a pointer to the image after
%      reading.  A null image is returned if there is a memory shortage or
%      if the image cannot be read.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o exception: return any errors or warnings in this structure.
%
%  To do, more or less in chronological order (as of version 5.5.2,
%   November 26, 2002 -- glennrp -- see also "To do" under WriteMNGImage):
%
%    Get 16-bit cheap transparency working.
%
%    (At this point, PNG decoding is supposed to be in full MNG-LC compliance)
%
%    Preserve all unknown and not-yet-handled known chunks found in input
%    PNG file and copy them into output PNG files according to the PNG
%    copying rules.
%
%    (At this point, PNG encoding should be in full MNG compliance)
%
%    Provide options for choice of background to use when the MNG BACK
%    chunk is not present or is not mandatory (i.e., leave transparent,
%    user specified, MNG BACK, PNG bKGD)
%
%    Implement LOOP/ENDL [done, but could do discretionary loops more
%    efficiently by linking in the duplicate frames.].
%
%    Decode and act on the MHDR simplicity profile (offer option to reject
%    files or attempt to process them anyway when the profile isn't LC or VLC).
%
%    Upgrade to full MNG without Delta-PNG.
%
%        o  BACK [done a while ago except for background image ID]
%        o  MOVE [done 15 May 1999]
%        o  CLIP [done 15 May 1999]
%        o  DISC [done 19 May 1999]
%        o  SAVE [partially done 19 May 1999 (marks objects frozen)]
%        o  SEEK [partially done 19 May 1999 (discard function only)]
%        o  SHOW
%        o  PAST
%        o  BASI
%        o  MNG-level tEXt/iTXt/zTXt
%        o  pHYg
%        o  pHYs
%        o  sBIT
%        o  bKGD
%        o  iTXt (wait for libpng implementation).
%
%    Use the scene signature to discover when an identical scene is
%    being reused, and just point to the original image->pixels instead
%    of storing another set of pixels.  This is not specific to MNG
%    but could be applied generally.
%
%    Upgrade to full MNG with Delta-PNG.
%
%    JNG tEXt/iTXt/zTXt
*/

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

/*
  This is the function that does the actual reading of data.  It is
  the same as the one supplied in libpng, except that it receives the
  datastream from the ReadBlob() function instead of standard input.
*/
static void png_get_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  Image
    *image;

  image=(Image *) png_get_io_ptr(png_ptr);
  if (length)
    {
      png_size_t
        check;

      check=(png_size_t) ReadBlob(image,(size_t) length,(char *) data);
      if (check != length)
        {
          char
            msg[MaxTextExtent];

          sprintf(msg,"Expected %lu bytes; found %lu bytes",
             (unsigned long) length,(unsigned long) check);
          png_warning(png_ptr,msg);
          png_error(png_ptr,"Read Exception");
        }
    }
}

#if !defined(PNG_READ_EMPTY_PLTE_SUPPORTED) && \
    !defined(PNG_MNG_FEATURES_SUPPORTED)
/* We use mng_get_data() instead of png_get_data() if we have a libpng
 * older than libpng-1.0.3a, which was the first to allow the empty
 * PLTE, or a newer libpng in which PNG_MNG_FEATURES_SUPPORTED was
 * ifdef'ed out.  Earlier versions would crash if the bKGD chunk was
 * encountered after an empty PLTE, so we have to look ahead for bKGD
 * chunks and remove them from the datastream that is passed to libpng,
 * and store their contents for later use.
 */
static void mng_get_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  MngInfo
    *mng_info;

  Image
    *image;

  png_size_t
    check;

  register long
    i;

  i=0;
  mng_info=(MngInfo *) png_get_io_ptr(png_ptr);
  image=(Image *) mng_info->image;
  while (mng_info->bytes_in_read_buffer && length)
  {
    data[i]=mng_info->read_buffer[i];
    mng_info->bytes_in_read_buffer--;
    length--;
    i++;
  }
  if (length)
    {
      check=(png_size_t) ReadBlob(image,(size_t) length,(char *) data);
      if (check != length)
        png_error(png_ptr,"Read Exception");
      if (length == 4)
        {
          if ((data[0] == 0) && (data[1] == 0) && (data[2] == 0) &&
              (data[3] == 0))
            {
              check=(png_size_t) ReadBlob(image,(size_t) length,
                (char *) mng_info->read_buffer);
              mng_info->read_buffer[4]=0;
              mng_info->bytes_in_read_buffer=4;
              if (!memcmp(mng_info->read_buffer,mng_PLTE,4))
                mng_info->found_empty_plte=True;
              if (!memcmp(mng_info->read_buffer,mng_IEND,4))
                {
                  mng_info->found_empty_plte=False;
                  mng_info->have_saved_bkgd_index=False;
                }
            }
          if ((data[0] == 0) && (data[1] == 0) && (data[2] == 0) &&
              (data[3] == 1))
            {
              check=(png_size_t) ReadBlob(image,(size_t) length,
                (char *) mng_info->read_buffer);
              mng_info->read_buffer[4]=0;
              mng_info->bytes_in_read_buffer=4;
              if (!memcmp(mng_info->read_buffer,mng_bKGD,4))
                if (mng_info->found_empty_plte)
                  {
                    /*
                      Skip the bKGD data byte and CRC.
                    */
                    check=(png_size_t)
                      ReadBlob(image,5,(char *) mng_info->read_buffer);
                    check=(png_size_t) ReadBlob(image,(size_t) length,
                      (char *) mng_info->read_buffer);
                    mng_info->saved_bkgd_index=mng_info->read_buffer[0];
                    mng_info->have_saved_bkgd_index=True;
                    mng_info->bytes_in_read_buffer=0;
                  }
            }
        }
    }
}
#endif

static void png_put_data(png_structp png_ptr,png_bytep data,png_size_t length)
{
  Image
    *image;

  image=(Image *) png_get_io_ptr(png_ptr);
  if (length)
    {
      png_size_t
        check;

      check=(png_size_t) WriteBlob(image,(unsigned long) length,(char *) data);
      if (check != length)
        png_error(png_ptr,"WriteBlob Failed");
    }
}

static void png_flush_data(png_structp png_ptr)
{
  (void) png_ptr;
  /* There is currently no safe API to "flush" a blob. */
#if 0
  Image
    *image;

  image=(Image *) png_get_io_ptr(png_ptr);
  (void) SyncBlob(image);
#endif
}

#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
static int PalettesAreEqual(Image *a,Image *b)
{
  long
    i;

  if ((a == (Image *) NULL) || (b == (Image *) NULL))
    return((int) False);
  if (a->storage_class!=PseudoClass || b->storage_class!=PseudoClass)
    return((int) False);
  if (a->colors != b->colors)
    return((int) False);
  for (i=0; i < (long) a->colors; i++)
  {
    if ((a->colormap[i].red != b->colormap[i].red) ||
        (a->colormap[i].green != b->colormap[i].green) ||
        (a->colormap[i].blue != b->colormap[i].blue))
      return((int) False);
  }
  return((int) True);
}
#endif

static void MngInfoDiscardObject(MngInfo *mng_info,int i)
{
  if (i && (i < MNG_MAX_OBJECTS) && (mng_info != (MngInfo *) NULL) &&
      mng_info->exists[i] && !mng_info->frozen[i])
    {
#ifdef MNG_OBJECT_BUFFERS
      if (mng_info->ob[i] != (MngBuffer *) NULL)
        {
          if (mng_info->ob[i]->reference_count > 0)
            mng_info->ob[i]->reference_count--;
          if (mng_info->ob[i]->reference_count == 0)
            {
              if (mng_info->ob[i]->image != (Image *) NULL)
                DestroyImage(mng_info->ob[i]->image);
              MagickFreeMemory(mng_info->ob[i]);
            }
        }
      mng_info->ob[i]=(MngBuffer *) NULL;
#endif
      mng_info->exists[i]=False;
      mng_info->invisible[i]=False;
      mng_info->viewable[i]=False;
      mng_info->frozen[i]=False;
      mng_info->x_off[i]=0;
      mng_info->y_off[i]=0;
      mng_info->object_clip[i].left=0;
      mng_info->object_clip[i].right=PNG_MAX_UINT;
      mng_info->object_clip[i].top=0;
      mng_info->object_clip[i].bottom=PNG_MAX_UINT;
    }
}

static void MngInfoFreeStruct(MngInfo *mng_info,int *have_mng_structure)
{
  if (*have_mng_structure && (mng_info != (MngInfo *) NULL))
    {
      register long
        i;

      for (i=1; i < MNG_MAX_OBJECTS; i++)
        MngInfoDiscardObject(mng_info,i);
      if (mng_info->global_plte != (png_colorp) NULL)
        MagickFreeMemory(mng_info->global_plte);
      MagickFreeMemory(mng_info);
      *have_mng_structure=False;
    }
}

static MngBox mng_minimum_box(MngBox box1,MngBox box2)
{
  MngBox
    box;

  box=box1;
  if (box.left < box2.left)
    box.left=box2.left;
  if (box.top < box2.top)
    box.top=box2.top;
  if (box.right > box2.right)
    box.right=box2.right;
  if (box.bottom > box2.bottom)
    box.bottom=box2.bottom;
  return box;
}

static MngBox mng_read_box(MngBox previous_box,char delta_type,unsigned char *p)
{
   MngBox
      box;

  /*
    Read clipping boundaries from DEFI, CLIP, FRAM, or PAST chunk.
  */
  box.left=(long) ((p[0]  << 24) | (p[1]  << 16) | (p[2]  << 8) | p[3]);
  box.right=(long) ((p[4]  << 24) | (p[5]  << 16) | (p[6]  << 8) | p[7]);
  box.top=(long) ((p[8]  << 24) | (p[9]  << 16) | (p[10] << 8) | p[11]);
  box.bottom=(long) ((p[12] << 24) | (p[13] << 16) | (p[14] << 8) | p[15]);
  if (delta_type != 0)
    {
      box.left+=previous_box.left;
      box.right+=previous_box.right;
      box.top+=previous_box.top;
      box.bottom+=previous_box.bottom;
    }
  return(box);
}

static MngPair mng_read_pair(MngPair previous_pair,int delta_type,
  unsigned char *p)
{
  MngPair
    pair;
  /*
    Read two longs from CLON, MOVE or PAST chunk
  */
  pair.a=(long) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
  pair.b=(long) ((p[4] << 24) | (p[5] << 16) | (p[6] << 8) | p[7]);
  if (delta_type != 0)
    {
      pair.a+=previous_pair.a;
      pair.b+=previous_pair.b;
    }
  return(pair);
}

static long mng_get_long(unsigned char *p)
{
  return((long) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]));
}

static void PNGErrorHandler(png_struct *ping,png_const_charp message)
{
  Image
    *image;

  image=(Image *) png_get_error_ptr(ping);
  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  libpng-%.1024s error: %.1024s", PNG_LIBPNG_VER_STRING,
      message);
  (void) ThrowException2(&image->exception,CoderError,message,image->filename);
  longjmp(ping->jmpbuf,1);
}

static void PNGWarningHandler(png_struct *ping,png_const_charp message)
{
  Image
    *image;

  if (LocaleCompare(message, "Missing PLTE before tRNS") == 0)
    png_error(ping, message);
  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
      "  libpng-%.1024s warning: %.1024s", PNG_LIBPNG_VER_STRING,
      message);
  image=(Image *) png_get_error_ptr(ping);
  (void) ThrowException2(&image->exception,CoderWarning,message,image->filename);
}

#ifdef PNG_USER_MEM_SUPPORTED
static png_voidp png_IM_malloc(png_structp png_ptr,png_uint_32 size)
{
#if (PNG_LIBPNG_VER < 10011)
  png_voidp
    ret;

  png_ptr=png_ptr;
  ret=MagickAllocateMemory(png_voidp,(size_t) size);
  if (ret == NULL)
    png_error("Insufficient memory.");
  return (ret);
#else
  png_ptr=png_ptr;
  return MagickAllocateMemory(png_voidp,(size_t) size);
#endif
}

/*
  Free a pointer.  It is removed from the list at the same time.
*/
static png_free_ptr png_IM_free(png_structp png_ptr,png_voidp ptr)
{
  png_ptr=png_ptr;
  MagickFreeMemory(ptr);
  return((png_free_ptr) NULL);
}
#endif

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

static int
png_read_raw_profile(Image *image, const ImageInfo *image_info,
   png_textp text,int ii)
{
  unsigned char
    *info;

  register long
    i;

  register unsigned char
    *dp;

  register png_charp
    sp;

  png_uint_32
    length,
    nibbles;

  unsigned char
    unhex[103]={0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,1, 2,3,4,5,6,7,8,9,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,
                 0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,10,11,12,
                 13,14,15};

  sp=text[ii].text+1;
  /* look for newline */
  while (*sp != '\n')
     sp++;
  /* look for length */
  while (*sp == '\0' || *sp == ' ' || *sp == '\n')
     sp++;
  length=atol(sp);
  while (*sp != ' ' && *sp != '\n')
     sp++;
  /* allocate space */
  if (length == 0)
  {
    (void) ThrowException(&image->exception,CoderError,UnableToCopyProfile,
      "invalid profile length");
    return (False);
  }
  info=MagickAllocateMemory(unsigned char *,length);
  if (info == (unsigned char *) NULL)
  {
    (void) ThrowException(&image->exception,ResourceLimitError,MemoryAllocationFailed,"unable to copy profile");
    return (False);
  }
  /* copy profile, skipping white space and column 1 "=" signs */
  dp=info;
  nibbles=length*2;
  for (i=0; i < (long) nibbles; i++)
  {
    while (*sp < '0' || (*sp > '9' && *sp < 'a') || *sp > 'f')
    {
      if (*sp == '\0')
        {
          (void) ThrowException(&image->exception,CoderError,UnableToCopyProfile,
            "ran out of data");
          MagickFreeMemory(info);
          return (False);
        }
      sp++;
    }
    if (i%2 == 0)
      *dp=16*unhex[(int) *sp++];
    else
      (*dp++)+=unhex[(int) *sp++];
  }

  /* We have already read "Raw profile type " */
  if (!memcmp(&text[ii].key[17], "iptc\0",5))
    {
      image->iptc_profile.length=length;
      image->iptc_profile.info=info;
      if (image_info->verbose)
        (void) printf(" Found an IPTC profile.\n");
    }
  else if (!memcmp(&text[ii].key[17], "icm\0",4))
    {
      image->color_profile.length=length;
      image->color_profile.info=info;
      if (image_info->verbose)
        (void) printf(" Found an ICM (ICCP) profile.\n");
    }
  else
    {
      i=(long) image->generic_profiles;
      if (image->generic_profile == (ProfileInfo *) NULL)
        image->generic_profile=MagickAllocateMemory(ProfileInfo *,
           sizeof(ProfileInfo));
      else
        MagickReallocMemory(image->generic_profile,
           (i+1)*sizeof(ProfileInfo));
      image->generic_profile[i].length=length;
      image->generic_profile[i].name=AllocateString(&text[ii].key[17]);
      image->generic_profile[i].info=info;
      image->generic_profiles++;
      if (image_info->verbose)
        (void) printf(" Found a generic profile, type %.1024s\n",
           &text[ii].key[17]);
    }
  return True;
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d O n e P N G I m a g e                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method ReadOnePNGImage reads a Portable Network Graphics (PNG) image file
%  (minus the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  The format of the ReadOnePNGImage method is:
%
%      Image *ReadOnePNGImage(MngInfo *mng_info, const ImageInfo *image_info,
%         ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image:  Method ReadOnePNGImage returns a pointer to the image after
%      reading.  A null image is returned if there is a memory shortage or
%      if the image cannot be read.
%
%    o mng_info: Specifies a pointer to a MngInfo structure.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static Image *ReadOnePNGImage(MngInfo *mng_info,
    const ImageInfo *image_info, ExceptionInfo *exception)
{
  /* Read one PNG image */

  Image
    *image;

  int
    logging,
    num_text,
    num_passes,
    pass;

  PixelPacket
    transparent_color;

  png_info
    *end_info,
    *ping_info;

  png_struct
    *ping;

  png_textp
    text;

  unsigned char
    *png_pixels;

  long
    y;

  register unsigned char
    *p;

  register IndexPacket
    *indexes;

  register long
    i,
    x;

  register PixelPacket
    *q;

  unsigned long
    length,
    row_offset;

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  png_byte unused_chunks[]=
       {
        104,  73,  83,  84, '\0',   /* hIST */
        105,  84,  88, 116, '\0',   /* iTXt */
        112,  67,  65,  76, '\0',   /* pCAL */
        115,  67,  65,  76, '\0',   /* sCAL */
        115,  80,  76,  84, '\0',   /* sPLT */
        116,  73,  77,  69, '\0',   /* tIME */
        };
#endif

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
      "  enter ReadOnePNGImage()");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  AcquireSemaphoreInfo(&png_semaphore);
#endif

#if (PNG_LIBPNG_VER < 10007)
  if (image_info->verbose)
    printf("Your PNG library (libpng-%s) is rather old.\n",
       PNG_LIBPNG_VER_STRING);
#endif

  image=mng_info->image;

  /*
    Allocate the PNG structures
  */
#ifdef PNG_USER_MEM_SUPPORTED
 ping=png_create_read_struct_2(PNG_LIBPNG_VER_STRING, image,
   PNGErrorHandler,PNGWarningHandler, NULL,
   (png_malloc_ptr) png_IM_malloc,(png_free_ptr) png_IM_free);
#else
  ping=png_create_read_struct(PNG_LIBPNG_VER_STRING,image,
    PNGErrorHandler,PNGWarningHandler);
#endif
  if (ping == (png_struct *) NULL)
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
  ping_info=png_create_info_struct(ping);
  if (ping_info == (png_info *) NULL)
    {
      png_destroy_read_struct(&ping,(png_info **) NULL,(png_info **) NULL);
      ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image)
    }
  end_info=png_create_info_struct(ping);
  if (end_info == (png_info *) NULL)
    {
      png_destroy_read_struct(&ping,&ping_info,(png_info **) NULL);
      ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image)
    }
  png_pixels=(unsigned char *) NULL;
  if (setjmp(ping->jmpbuf))
    {
      /*
        PNG image is corrupt.
      */
      png_destroy_read_struct(&ping,&ping_info,&end_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      LiberateSemaphoreInfo(&png_semaphore);
#endif
      if (png_pixels != (unsigned char *) NULL)
        MagickFreeMemory(png_pixels);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  exit ReadOnePNGImage() with error.");
      if (image != (Image *) NULL)
        {
          if (image->exception.severity > exception->severity)
            CopyException(exception,&image->exception);
          image->columns=0;
        }

      return(image);
    }
  /*
    Prepare PNG for reading.
  */
  mng_info->image_found++;
  png_set_sig_bytes(ping,8);
  if (LocaleCompare(image_info->magick,"MNG") == 0)
    {
#if defined(PNG_MNG_FEATURES_SUPPORTED)
      png_permit_mng_features(ping,PNG_ALL_MNG_FEATURES);
      png_set_read_fn(ping,image,png_get_data);
#else
#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED)
      png_permit_empty_plte(ping,True);
      png_set_read_fn(ping,image,png_get_data);
#else
      mng_info->image=image;
      mng_info->bytes_in_read_buffer=0;
      mng_info->found_empty_plte=False;
      mng_info->have_saved_bkgd_index=False;
      png_set_read_fn(ping,mng_info,mng_get_data);
#endif
#endif
    }
  else
    png_set_read_fn(ping,image,png_get_data);

#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  /* Ignore unused chunks */
  png_set_keep_unknown_chunks(ping, 1, unused_chunks,
     (int)sizeof(unused_chunks)/5);
#endif

#if defined(PNG_USE_PNGGCCRD) && defined(PNG_ASSEMBLER_CODE_SUPPORTED) \
&& (PNG_LIBPNG_VER >= 10200)
  /* Disable thread-unsafe features of pnggccrd */
  if (png_access_version_number() >= 10200)
  {
    png_uint_32 mmx_disable_mask=0;
    png_uint_32 asm_flags;

    mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
                        | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
    asm_flags=png_get_asm_flags(ping);
    png_set_asm_flags(ping, asm_flags & ~mmx_disable_mask);
  }
#endif

  png_read_info(ping,ping_info);

#if (QuantumDepth == 8)
  image->depth=8;
#else
  if (ping_info->bit_depth > 8)
    image->depth=16;
  else
    image->depth=8;
#endif

  if (ping_info->bit_depth < 8)
    {
      if ((ping_info->color_type == PNG_COLOR_TYPE_PALETTE))
        {
          png_set_packing(ping);
          image->depth=8;
        }
    }
  if (logging)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG width: %lu, height: %lu",
          ping_info->width, ping_info->height);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG color_type: %d, bit_depth: %d",
          ping_info->color_type, ping_info->bit_depth);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG compression_method: %d",
          ping_info->compression_type);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG interlace_method: %d, filter_method: %d",
          ping_info->interlace_type,ping_info->filter_type);
    }

#if (PNG_LIBPNG_VER > 10008) && defined(PNG_READ_iCCP_SUPPORTED)
  if (ping_info->valid & PNG_INFO_iCCP)
    {
      int
        compression;

      png_charp
        info,
        name;

      (void) png_get_iCCP(ping,ping_info,&name,(int *) &compression,&info,
        (png_uint_32 *) &image->color_profile.length);

      if (image->color_profile.name)
         MagickFreeMemory(image->color_profile.name);
      if (image->color_profile.info)
          MagickFreeMemory(image->color_profile.info);
      if (image->color_profile.length)
        {
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Reading PNG iCCP chunk.");
#ifdef PNG_FREE_ME_SUPPORTED
          image->color_profile.name=AllocateString("icm");
          image->color_profile.info=(unsigned char *) info;
          png_data_freer(ping, ping_info, PNG_USER_WILL_FREE_DATA,
             PNG_FREE_ICCP);
#else
          /* libpng will destroy name and info so we must copy them now. */
          image->color_profile.info=MagickAllocateMemory(unsigned char *,length);
          if (image->color_profile.info == (unsigned char *) NULL)
            {
               MagickError3(ResourceLimitError,MemoryAllocationFailed,
                UnableToAllocateICCProfile);
               image->color_profile.length=0;
            }
          else
            {
               (void) memcpy(image->color_profile.info,
                  (unsigned char *) info,length);
               image->color_profile.name=AllocateString("icm");
               /* Note that the PNG iCCP profile name gets lost. */
            }
#endif
      }

    }
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
  {
    int
      intent;

    if (mng_info->have_global_srgb)
      image->rendering_intent=(RenderingIntent)
        (mng_info->global_srgb_intent+1);
    if (png_get_sRGB(ping,ping_info,&intent))
      {
        image->rendering_intent=(RenderingIntent) (intent+1);
        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Reading PNG sRGB chunk: rendering_intent: %d",intent+1);
      }
  }
#endif
  {
     double
        file_gamma;

     if (mng_info->have_global_gama)
       image->gamma=mng_info->global_gamma;
     if (png_get_gAMA(ping,ping_info,&file_gamma))
       {
         image->gamma=(float) file_gamma;
         if (logging)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Reading PNG gAMA chunk: gamma: %f",file_gamma);
       }
  }
  if (mng_info->have_global_chrm)
    image->chromaticity=mng_info->global_chrm;
  if (ping_info->valid & PNG_INFO_cHRM)
    {
      (void) png_get_cHRM(ping,ping_info,
        &image->chromaticity.white_point.x,
        &image->chromaticity.white_point.y,
        &image->chromaticity.red_primary.x,
        &image->chromaticity.red_primary.y,
        &image->chromaticity.green_primary.x,
        &image->chromaticity.green_primary.y,
        &image->chromaticity.blue_primary.x,
        &image->chromaticity.blue_primary.y);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG cHRM chunk.");
    }
  if (image->rendering_intent)
    {
      image->gamma=0.45455f;
      image->chromaticity.red_primary.x=0.6400f;
      image->chromaticity.red_primary.y=0.3300f;
      image->chromaticity.green_primary.x=0.3000f;
      image->chromaticity.green_primary.y=0.6000f;
      image->chromaticity.blue_primary.x=0.1500f;
      image->chromaticity.blue_primary.y=0.0600f;
      image->chromaticity.white_point.x=0.3127f;
      image->chromaticity.white_point.y=0.3290f;
    }
  if (mng_info->have_global_gama || image->rendering_intent)
    ping_info->valid|=PNG_INFO_gAMA;
  if (mng_info->have_global_chrm || image->rendering_intent)
    ping_info->valid|=PNG_INFO_cHRM;
#if defined(PNG_oFFs_SUPPORTED)
  if (mng_info->mng_type == 0 && (ping_info->valid & PNG_INFO_oFFs))
    {
       image->page.x=png_get_x_offset_pixels(ping, ping_info);
       image->page.y=png_get_y_offset_pixels(ping, ping_info);
       if (logging)
         if (image->page.x || image->page.y)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Reading PNG oFFs chunk: x: %ld, y: %ld.",image->page.x,
               image->page.y);
    }
#endif
#if defined(PNG_pHYs_SUPPORTED)
  if (ping_info->valid & PNG_INFO_pHYs)
    {
      int
        unit_type;

      png_uint_32
        x_resolution,
        y_resolution;

      /*
        Set image resolution.
      */
      (void) png_get_pHYs(ping,ping_info,&x_resolution,&y_resolution,
          &unit_type);
      image->x_resolution=(float) x_resolution;
      image->y_resolution=(float) y_resolution;
      if (unit_type == PNG_RESOLUTION_METER)
        {
          image->units=PixelsPerCentimeterResolution;
          image->x_resolution=(double) x_resolution/100.0;
          image->y_resolution=(double) y_resolution/100.0;
        }
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG pHYs chunk: xres: %lu, yres: %lu, units: %d.",
            x_resolution, y_resolution, unit_type);
    }
  else
    {
      if (mng_info->have_global_phys)
        {
          image->x_resolution=(float) mng_info->global_x_pixels_per_unit;
          image->y_resolution=(float) mng_info->global_y_pixels_per_unit;
          if (mng_info->global_phys_unit_type == PNG_RESOLUTION_METER)
            {
              image->units=PixelsPerCentimeterResolution;
              image->x_resolution=(double)
                mng_info->global_x_pixels_per_unit/100.0;
              image->y_resolution=(double)
                mng_info->global_y_pixels_per_unit/100.0;
            }
          ping_info->valid|=PNG_INFO_pHYs;
        }
    }
#endif
  if (ping_info->valid & PNG_INFO_PLTE)
    {
      int
        number_colors;

      png_colorp
        palette;

      (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);
      if (number_colors == 0 && ping_info->color_type ==
          PNG_COLOR_TYPE_PALETTE)
        {
          if (mng_info->global_plte_length)
            {
              png_set_PLTE(ping,ping_info,mng_info->global_plte,
                (int) mng_info->global_plte_length);
              if (!(ping_info->valid & PNG_INFO_tRNS))
                if (mng_info->global_trns_length)
                  {
                    if (mng_info->global_trns_length >
                        mng_info->global_plte_length)
                      (void) ThrowException2(&image->exception,CoderError,
                        "global tRNS has more entries than global PLTE",
                        image_info->filename);
                    png_set_tRNS(ping,ping_info,mng_info->global_trns,
                      (int) mng_info->global_trns_length,NULL);
                  }
#if defined(PNG_READ_bKGD_SUPPORTED)
              if (
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
                   mng_info->have_saved_bkgd_index ||
#endif
                   ping_info->valid & PNG_INFO_bKGD)
                    {
                      png_color_16
                         background;

#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
                      if (mng_info->have_saved_bkgd_index)
                        background.index=mng_info->saved_bkgd_index;
                      else
#endif
                        background.index=ping_info->background.index;
                      background.red=(png_uint_16)
                        mng_info->global_plte[background.index].red;
                      background.green=(png_uint_16)
                        mng_info->global_plte[background.index].green;
                      background.blue=(png_uint_16)
                        mng_info->global_plte[background.index].blue;
                      png_set_bKGD(ping,ping_info,&background);
                    }
#endif
                }
              else
                (void) ThrowException2(&image->exception,CoderError,
                  "No global PLTE in file",image_info->filename);
            }
        }

#if defined(PNG_READ_bKGD_SUPPORTED)
  if (mng_info->have_global_bkgd && !(ping_info->valid & PNG_INFO_bKGD))
      image->background_color=mng_info->mng_global_bkgd;
  if (ping_info->valid & PNG_INFO_bKGD)
    {
      /*
        Set image background color.
      */
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG bKGD chunk.");
      if (ping_info->bit_depth <= QuantumDepth)
        {
          image->background_color.red=ping_info->background.red;
          image->background_color.green=ping_info->background.green;
          image->background_color.blue=ping_info->background.blue;
        }
      else
        {
          image->background_color.red=
            ScaleShortToQuantum(ping_info->background.red);
          image->background_color.green=
            ScaleShortToQuantum(ping_info->background.green);
          image->background_color.blue=
            ScaleShortToQuantum(ping_info->background.blue);
        }
    }
#endif
  if (ping_info->valid & PNG_INFO_tRNS)
    {
      int
        scale;

      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG tRNS chunk.");
      scale=(int) (MaxRGB/((1L << ping_info->bit_depth)-1L));
      if (scale < 1)
         scale=1;
      /*
        Image has a transparent background.
      */
      transparent_color.red=(int) (ping_info->trans_values.red*scale);
      transparent_color.green=(int) (ping_info->trans_values.green*scale);
      transparent_color.blue=(int) (ping_info->trans_values.blue*scale);
      transparent_color.opacity=(int) (ping_info->trans_values.gray*scale);
      if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
        {
          transparent_color.red=transparent_color.opacity;
          transparent_color.green=transparent_color.opacity;
          transparent_color.blue=transparent_color.opacity;
        }
    }
#if defined(PNG_READ_sBIT_SUPPORTED)
  if (mng_info->have_global_sbit)
    {
      int
         not_valid;
      not_valid=!ping_info->valid;
      if (not_valid & PNG_INFO_sBIT)
        png_set_sBIT(ping,ping_info,&mng_info->global_sbit);
    }
#endif
  num_passes=png_set_interlace_handling(ping);
  png_read_update_info(ping,ping_info);
  /*
    Initialize image structure.
  */
  mng_info->image_box.left=0;
  mng_info->image_box.right=(long) ping_info->width;
  mng_info->image_box.top=0;
  mng_info->image_box.bottom=(long) ping_info->height;
  if (mng_info->mng_type == 0)
    {
      mng_info->mng_width=ping_info->width;
      mng_info->mng_height=ping_info->height;
      mng_info->frame=mng_info->image_box;
      mng_info->clip=mng_info->image_box;
    }
  else
    {
      image->page.y=mng_info->y_off[mng_info->object_id];
    }
  image->compression=ZipCompression;
  image->columns=ping_info->width;
  image->rows=ping_info->height;
  if ((ping_info->color_type == PNG_COLOR_TYPE_PALETTE) ||
      (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
      (ping_info->color_type == PNG_COLOR_TYPE_GRAY))
    {
      image->storage_class=PseudoClass;
      image->colors=1 << ping_info->bit_depth;
#if (QuantumDepth == 8)
      if (image->colors > 256)
        image->colors=256;
#else
      if (image->colors > 65536L)
        image->colors=65536L;
#endif
      if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
        {
          int
            number_colors;

          png_colorp
            palette;

          (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);
          image->colors=number_colors;
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Reading PNG PLTE chunk: number_colors: %d.",number_colors);
        }
    }

  if (image->storage_class == PseudoClass)
    {
      /*
        Initialize image colormap.
      */
      if (!AllocateImageColormap(image,image->colors))
        ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
      if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
        {
          int
            number_colors;

          png_colorp
            palette;

          (void) png_get_PLTE(ping,ping_info,&palette,&number_colors);
          for (i=0; i < (long) image->colors; i++)
          {
            image->colormap[i].red=ScaleCharToQuantum(palette[i].red);
            image->colormap[i].green=ScaleCharToQuantum(palette[i].green);
            image->colormap[i].blue=ScaleCharToQuantum(palette[i].blue);
          }
        }
      else
        {
          unsigned long
            scale;

          scale=(MaxRGB/((1 << ping_info->bit_depth)-1));
          if (scale < 1)
             scale=1;
          for (i=0; i < (long) image->colors; i++)
          {
            image->colormap[i].red=(Quantum) (i*scale);
            image->colormap[i].green=(Quantum) (i*scale);
            image->colormap[i].blue=(Quantum) (i*scale);
          }
       }
    }
  /*
    Read image scanlines.
  */
  if (image->delay != 0)
    mng_info->scenes_found++;
  if (image_info->ping && (image_info->number_scenes != 0) &&
      mng_info->scenes_found > (long) (image_info->first_scene+image_info->number_scenes))
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Skipping PNG image data for scene %ld",
            mng_info->scenes_found-1);
      png_destroy_read_struct(&ping,&ping_info,&end_info);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      LiberateSemaphoreInfo(&png_semaphore);
#endif
      if (image != (Image *) NULL)
        image->columns=0;
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  exit ReadOnePNGImage().");
      return (image);
    }
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Reading PNG IDAT chunk(s)");
  if (num_passes > 1)
    png_pixels=MagickAllocateMemory(unsigned char *,
      ping_info->rowbytes*image->rows);
  else
    png_pixels=MagickAllocateMemory(unsigned char *,
      ping_info->rowbytes);
  if (png_pixels == (unsigned char *) NULL)
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Converting PNG pixels to pixel packets");
  /*
    Convert PNG pixels to pixel packets.
  */
  if (image->storage_class == DirectClass)
    for (pass=0; pass < num_passes; pass++)
    {
      /*
        Convert image to DirectClass pixel packets.
      */
#if (QuantumDepth == 8)
      int
        depth;

      depth=(long) image->depth;
#endif
      image->matte=((ping_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) ||
          (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
          (ping_info->valid & PNG_INFO_tRNS));

      for (y=0; y < (long) image->rows; y++)
      {
        if (num_passes > 1)
          row_offset=ping_info->rowbytes*y;
        else
          row_offset=0;
        png_read_row(ping,png_pixels+row_offset,NULL);
        if (!GetImagePixels(image,0,y,image->columns,1))
          break;
#if (QuantumDepth == 8)
        if (depth == 16)
          {
            register Quantum
              *p,
              *r;

            r=png_pixels+row_offset;
            p=r;
            if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
              {
                for (x=(long) image->columns; x > 0; x--)
                {
                  *r++=*p++;
                  p++;
                  if ((ping_info->valid & PNG_INFO_tRNS) &&
                     (((*(p-2) << 8)|*(p-1)) == transparent_color.opacity))
                    {
                       /* Cheap transparency */
                       *r++=TransparentOpacity;
                    }
                  else
                       *r++=OpaqueOpacity;
                }
              }
            else if (ping_info->color_type == PNG_COLOR_TYPE_RGB)
              {
              if (ping_info->valid & PNG_INFO_tRNS)
                for (x=(long) image->columns; x > 0; x--)
                {
                  *r++=*p++;
                  p++;
                  *r++=*p++;
                  p++;
                  *r++=*p++;
                  p++;
                  if ((((*(p-6) << 8)|*(p-5)) == transparent_color.red) &&
                       (((*(p-4) << 8)|*(p-3)) == transparent_color.green) &&
                       (((*(p-2) << 8)|*(p-1)) == transparent_color.blue))
                    {
                       /* Cheap transparency */
                       *r++=TransparentOpacity;
                    }
                  else
                       *r++=OpaqueOpacity;
                }
              else
                for (x=(long) image->columns; x > 0; x--)
                {
                  *r++=*p++;
                  p++;
                  *r++=*p++;
                  p++;
                  *r++=*p++;
                  p++;
                  *r++=OpaqueOpacity;
                }
              }
            else if (ping_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
              for (x=(long) (4*image->columns); x > 0; x--)
              {
                *r++=*p++;
                p++;
              }
            else if (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
              for (x=(long) (2*image->columns); x > 0; x--)
              {
                *r++=*p++;
                p++;
              }
          }
        if (depth == 8 && ping_info->color_type == PNG_COLOR_TYPE_GRAY)
          (void) PushImagePixels(image,(QuantumType) GrayQuantum,
            png_pixels+row_offset);
        if (ping_info->color_type == PNG_COLOR_TYPE_GRAY ||
            ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
          {
            image->depth=8;
            (void) PushImagePixels(image,(QuantumType) GrayAlphaQuantum,
              png_pixels+row_offset);
            image->depth=depth;
          }
        else if (depth == 8 && ping_info->color_type == PNG_COLOR_TYPE_RGB)
           (void) PushImagePixels(image,(QuantumType) RGBQuantum,
              png_pixels+row_offset);
        else if (ping_info->color_type == PNG_COLOR_TYPE_RGB ||
              ping_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          {
            image->depth=8;
            (void) PushImagePixels(image,(QuantumType) RGBAQuantum,
              png_pixels+row_offset);
            image->depth=depth;
          }
        else if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
            (void) PushImagePixels(image,(QuantumType) IndexQuantum,
              png_pixels+row_offset);
#else /* (QuantumDepth != 8) */

        if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
          (void) PushImagePixels(image,(QuantumType) GrayQuantum,
              png_pixels+row_offset);
        else if (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
          (void) PushImagePixels(image,(QuantumType) GrayAlphaQuantum,
              png_pixels+row_offset);
        else if (ping_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
          (void) PushImagePixels(image,(QuantumType) RGBAQuantum,
              png_pixels+row_offset);
        else if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
          (void) PushImagePixels(image,(QuantumType) IndexQuantum,
              png_pixels+row_offset);
        else
          (void) PushImagePixels(image,(QuantumType) RGBQuantum,
              png_pixels+row_offset);
#endif
        if (!SyncImagePixels(image))
          break;
      }
      if (image->previous == (Image *) NULL)
        if (!MagickMonitor(LoadImageTag,pass,num_passes,exception))
          break;
    }
  else /* image->storage_class != DirectClass */
    for (pass=0; pass < num_passes; pass++)
    {
      Quantum
        *quantum_scanline;

      register Quantum
        *r;

      /*
        Convert grayscale image to PseudoClass pixel packets.
      */
      image->matte=ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA;
      quantum_scanline=MagickAllocateMemory(Quantum *,(image->matte ?  2 : 1) *
         image->columns*sizeof(Quantum));
      if (quantum_scanline == (Quantum *) NULL)
        ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
      for (y=0; y < (long) image->rows; y++)
      {
        if (num_passes > 1)
          row_offset=ping_info->rowbytes*y;
        else
          row_offset=0;
        png_read_row(ping,png_pixels+row_offset,NULL);
        q=GetImagePixels(image,0,y,image->columns,1);
        if (q == (PixelPacket *) NULL)
          break;
        indexes=GetIndexes(image);
        p=png_pixels+row_offset;
        r=quantum_scanline;
        switch (ping_info->bit_depth)
        {
          case 1:
          {
            register long
              bit;

            for (x=(long) image->columns-7; x > 0; x-=8)
            {
              for (bit=7; bit >= 0; bit--)
                *r++=((*p) & (0x01 << bit) ? 0x01 : 0x00);
              p++;
            }
            if ((image->columns % 8) != 0)
              {
                for (bit=7; bit >= (long) (8-(image->columns % 8)); bit--)
                  *r++=((*p) & (0x01 << bit) ? 0x01 : 0x00);
              }
            break;
          }
          case 2:
          {
            for (x=(long) image->columns-3; x > 0; x-=4)
            {
              *r++=(*p >> 6) & 0x03;
              *r++=(*p >> 4) & 0x03;
              *r++=(*p >> 2) & 0x03;
              *r++=(*p++) & 0x03;
            }
            if ((image->columns % 4) != 0)
              {
                for (i=3; i >= (long) (4-(image->columns % 4)); i--)
                  *r++=(*p >> (i*2)) & 0x03;
              }
            break;
          }
          case 4:
          {
            for (x=(long) image->columns-1; x > 0; x-=2)
            {
              *r++=(*p >> 4) & 0x0f;
              *r++=(*p++) & 0x0f;
            }
            if ((image->columns % 2) != 0)
              *r++=(*p++ >> 4) & 0x0f;
            break;
          }
          case 8:
          {
            if (ping_info->color_type == 4)
              for (x=(long) image->columns; x > 0; x--)
              {
                *r++=*p++;
                /* In image.h, OpaqueOpacity is 0
                 * TransparentOpacity is MaxRGB
                 * In a PNG datastream, Opaque is MaxRGB
                 * and Transparent is 0.
                 */
                q->opacity=ScaleCharToQuantum(255-(*p++));
                q++;
              }
            else
              for (x=(long) image->columns; x > 0; x--)
                *r++=*p++;
            break;
          }
          case 16:
          {
            for (x=(long) image->columns; x > 0; x--)
            {
#if (QuantumDepth == 16)
              if (image->colors > 256)
                *r=((*p++) << 8);
              else
                *r=0;
              *r|=(*p++);
              r++;
              if (ping_info->color_type == 4)
                {
                  q->opacity=((*p++) << 8);
                  q->opacity|=(*p++);
                  q->opacity=(Quantum) (MaxRGB-q->opacity);
                  q++;
                }
#else
#if (QuantumDepth == 32)
              if (image->colors > 256)
                *r=((*p++) << 8);
              else
                *r=0;
              *r|=(*p++);
              r++;
              if (ping_info->color_type == 4)
                {
                  q->opacity=((*p++) << 8);
                  q->opacity|=(*p++);
                  q->opacity*=65537L;
                  q->opacity=(Quantum) (MaxRGB-q->opacity);
                  q++;
                }
#else /* QuantumDepth == 8 */
              *r++=(*p++);
              p++; /* strip low byte */
              if (ping_info->color_type == 4)
                {
                  q->opacity=(Quantum) (MaxRGB-(*p++));
                  p++;
                  q++;
                }
#endif
#endif
            }
            break;
          }
          default:
            break;
        }
        /*
          Transfer image scanline.
        */
        r=quantum_scanline;
        for (x=0; x < (long) image->columns; x++)
          indexes[x]=(*r++);
        if (!SyncImagePixels(image))
          break;
      }
      if (image->previous == (Image *) NULL)
        if (!MagickMonitor(LoadImageTag,pass,num_passes,exception))
          break;
      MagickFreeMemory(quantum_scanline);
    }
  if (image->storage_class == PseudoClass)
    SyncImage(image);
  png_read_end(ping,ping_info);

  if (image_info->number_scenes != 0 && mng_info->scenes_found-1 <
      (long) image_info->first_scene && image->delay != 0.)
    {
      png_destroy_read_struct(&ping,&ping_info,&end_info);
      MagickFreeMemory(png_pixels);
      image->colors=2;
      SetImage(image,TransparentOpacity);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      LiberateSemaphoreInfo(&png_semaphore);
#endif
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  exit ReadOnePNGImage().");
      return (image);
    }
  if (ping_info->valid & PNG_INFO_tRNS)
    {
      ClassType
        storage_class;

      /*
        Image has a transparent background.
      */
      storage_class=image->storage_class;
      image->matte=True;
      for (y=0; y < (long) image->rows; y++)
      {
        image->storage_class=storage_class;
        q=GetImagePixels(image,0,y,image->columns,1);
        if (q == (PixelPacket *) NULL)
          break;
        indexes=GetIndexes(image);

        q->opacity=OpaqueOpacity;
        if (storage_class == PseudoClass)
          {
            IndexPacket
              index;

            if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
              for (x=0; x < (long) image->columns; x++)
              {
                index=indexes[x];
                if (index < ping_info->num_trans)
                  q->opacity=
                    ScaleCharToQuantum(255-ping_info->trans[index]);
                q++;
              }
            else if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
              for (x=0; x < (long) image->columns; x++)
              {
                index=indexes[x];
                q->red=image->colormap[index].red;
                q->green=image->colormap[index].green;
                q->blue=image->colormap[index].blue;
                if (q->red == transparent_color.opacity)
                  q->opacity=TransparentOpacity;
                q++;
              }
          }
        else
          for (x=(long) image->columns; x > 0; x--)
          {
            if (q->red == transparent_color.red &&
                q->green == transparent_color.green &&
                q->blue == transparent_color.blue)
               q->opacity=TransparentOpacity;
            q++;
          }
        if (!SyncImagePixels(image))
          break;
      }
      image->storage_class=DirectClass;
    }
#if (QuantumDepth == 8)
  if (image->depth > 8)
    image->depth=8;
#endif
  if (png_get_text(ping,ping_info,&text,&num_text) != 0)
    for (i=0; i < (long) num_text; i++)
    {
      /* Check for a profile */

      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Reading PNG text chunk");
      if (!memcmp(text[i].key, "Raw profile type ",17))
          (void) png_read_raw_profile(image,image_info,text,(int) i);
      else
        {
          char
            *value;

          length=text[i].text_length;
          value=MagickAllocateMemory(char *,length+1);
          if (value == (char *) NULL)
            {
              (void) ThrowException3(&image->exception,ResourceLimitError,
                MemoryAllocationFailed,UnableToReadTextChunk);
              break;
            }
          *value='\0';
          (void) strncat(value,text[i].text,length);
          value[length]='\0';
          (void) SetImageAttribute(image,text[i].key,value);
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "      Keyword: %s",text[i].key);
          MagickFreeMemory(value);
        }
    }
#ifdef MNG_OBJECT_BUFFERS
  /*
    Store the object if necessary.
  */
  if (object_id && !mng_info->frozen[object_id])
    {
      if (mng_info->ob[object_id] == (MngBuffer *) NULL)
        {
          /*
            create a new object buffer.
          */
          mng_info->ob[object_id]=MagickAllocateMemory(MngBuffer *,
            sizeof(MngBuffer));
          if (mng_info->ob[object_id] != (MngBuffer *) NULL)
            {
              mng_info->ob[object_id]->image=(Image *) NULL;
              mng_info->ob[object_id]->reference_count=1;
            }
        }
      if ((mng_info->ob[object_id] == (MngBuffer *) NULL) ||
          mng_info->ob[object_id]->frozen)
        {
          if (mng_info->ob[object_id] == (MngBuffer *) NULL)
            (void) ThrowException(&image->exception,ResourceLimitError,MemoryAllocationFailed,image->filename);
          if (mng_info->ob[object_id]->frozen)
            (void) ThrowException(&image->exception,ResourceLimitError,
              "Cannot overwrite frozen MNG object buffer",image->filename);
        }
      else
        {
          png_uint_32
            width,
            height;

          int
            bit_depth,
            color_type,
            interlace_method,
            compression_method,
            filter_method;

          if (mng_info->ob[object_id]->image != (Image *) NULL)
            DestroyImage(mng_info->ob[object_id]->image);
          mng_info->ob[object_id]->image=CloneImage(image,0,0,True,
            &image->exception);
          if (mng_info->ob[object_id]->image != (Image *) NULL)
            mng_info->ob[object_id]->image->file=(FILE *) NULL;
          else
            (void) ThrowException(&image->exception,ResourceLimitError,
              "Cloning image for object buffer failed",image->filename);
          png_get_IHDR(ping,ping_info,&width,&height,&bit_depth,&color_type,
            &interlace_method,&compression_method,&filter_method);
          if (width > 250000L || height > 250000L)
             png_error(ping,"PNG Image dimensions are too large.");
          mng_info->ob[object_id]->width=width;
          mng_info->ob[object_id]->height=height;
          mng_info->ob[object_id]->color_type=color_type;
          mng_info->ob[object_id]->sample_depth=bit_depth;
          mng_info->ob[object_id]->interlace_method=interlace_method;
          mng_info->ob[object_id]->compression_method=compression_method;
          mng_info->ob[object_id]->filter_method=filter_method;
          if (ping_info->valid & PNG_INFO_PLTE)
            {
              int
                number_colors;

              png_colorp
                plte;

              /*
                Copy the PLTE to the object buffer.
              */
              png_get_PLTE(ping,ping_info,&plte,&number_colors);
              mng_info->ob[object_id]->plte_length=number_colors;
              for (i=0; i < number_colors; i++)
              {
                mng_info->ob[object_id]->plte[i]=plte[i];
              }
            }
          else
              mng_info->ob[object_id]->plte_length=0;
        }
    }
#endif
  /*
    Free memory.
  */
  png_destroy_read_struct(&ping,&ping_info,&end_info);

  MagickFreeMemory(png_pixels);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  LiberateSemaphoreInfo(&png_semaphore);
#endif

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  exit ReadOnePNGImage()");
  return (image);

/* end of reading one PNG image */
}

static Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *image,
    *previous;

  MngInfo
    *mng_info;

  char
    magic_number[MaxTextExtent];

  int
    have_mng_structure,
    logging;

  unsigned int
    status;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter ReadPNGImage()");
  image=AllocateImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == False)
    ThrowReaderException(FileOpenError,UnableToOpenFile,image);
  /*
    Verify PNG signature.
  */
  (void) ReadBlob(image,8,magic_number);
  if (memcmp(magic_number,"\211PNG\r\n\032\n",8) != 0)
    ThrowReaderException(CorruptImageError,ImproperImageHeader,image);
  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=False;
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=True;

  previous=image;
  image=ReadOnePNGImage(mng_info,image_info,exception);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (image == (Image *) NULL)
    {
      if (previous != (Image *) NULL)
        {
          CloseBlob(previous);
          DestroyImageList(previous);
        }
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "exit ReadPNGImage() with error");
      return((Image *) NULL);
    }
  CloseBlob(image);
  if (image->columns == 0 || image->rows == 0)
    {
      if (image->exception.severity > exception->severity)
        CopyException(exception,&image->exception);
      DestroyImageList(image);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "exit ReadPNGImage() with error.");
      return((Image *) NULL);
    }
  if (LocaleCompare(image_info->magick,"PNG8") == 0)
    {
      SetImageType(image,PaletteType);
      if (image->matte)
        {
          /* To do: Reduce to binary transparency */
        }
    }
  if (LocaleCompare(image_info->magick,"PNG24") == 0)
    {
      SetImageType(image,TrueColorType);
      image->matte=False;
    }
  if (LocaleCompare(image_info->magick,"PNG32") == 0)
      SetImageType(image,TrueColorMatteType);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadPNGImage()");
  return (image);
}



#if defined(JNG_SUPPORTED)
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d O n e J N G I m a g e                                             %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method ReadOneJNGImage reads a JPEG Network Graphics (JNG) image file
%  (minus the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  JNG support written by Glenn Randers-Pehrson, randeg@alum.rpi.edu.
%
%  The format of the ReadOneJNGImage method is:
%
%      Image *ReadOneJNGImage(MngInfo *mng_info, const ImageInfo *image_info,
%         ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image:  Method ReadOneJNGImage returns a pointer to the image after
%      reading.  A null image is returned if there is a memory shortage or
%      if the image cannot be read.
%
%    o mng_info: Specifies a pointer to a MngInfo structure.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o exception: return any errors or warnings in this structure.
%
*/
static Image *ReadOneJNGImage(MngInfo *mng_info,
    const ImageInfo *image_info, ExceptionInfo *exception)
{
  Image
    *alpha_image,
    *color_image,
    *image,
    *jng_image;

  ImageInfo
    *alpha_image_info,
    *color_image_info;

  long
    y;

  png_uint_32
    jng_height,
    jng_width;

  png_byte
    jng_color_type,
    jng_image_sample_depth,
    jng_image_compression_method,
    jng_image_interlace_method,
    jng_alpha_sample_depth,
    jng_alpha_compression_method,
    jng_alpha_filter_method,
    jng_alpha_interlace_method;

  register const PixelPacket
    *s;

  register long
    i,
    x;

  register PixelPacket
    *q;

  register unsigned char
    *p;

  unsigned int
    logging,
    read_JSEP,
    reading_idat,
    skip_to_iend,
    status;

  unsigned long
    length;

  jng_alpha_compression_method=0;
  jng_alpha_sample_depth=8;
  jng_color_type=0;
  jng_height=0;
  jng_width=0;
  alpha_image=(Image *) NULL;
  color_image=(Image *) NULL;
  alpha_image_info=(ImageInfo *) NULL;
  color_image_info=(ImageInfo *) NULL;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
      "  enter ReadOneJNGImage()");

  image=mng_info->image;
  if (GetPixels(image) != (PixelPacket *) NULL)
    {
      /*
        Allocate next image structure.
      */
      if (logging)
        LogMagickEvent(CoderEvent,GetMagickModule(),
            "  AllocateNextImage()");
      AllocateNextImage(image_info,image);
      if (image->next == (Image *) NULL)
        return((Image *) NULL);
      image=SyncNextImageInList(image);
    }
  mng_info->image=image;

  /*
    Signature bytes have already been read.
  */

  read_JSEP=False;
  reading_idat=False;
  skip_to_iend=False;
  for (;;)
  {
    char
      type[MaxTextExtent];

    unsigned char
      *chunk;

    unsigned int
      count;

    /*
      Read a new JNG chunk.
    */

    if (!MagickMonitor(LoadImagesTag,TellBlob(image),2*GetBlobSize(image),
        exception))
      break;

    type[0]='\0';
    (void) strcat(type,"errr");
    length=ReadBlobMSBLong(image);
    count=ReadBlob(image,4,type);

    if (logging)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Reading JNG chunk type %c%c%c%c, length: %lu",
          type[0],type[1],type[2],type[3],length);

    if (length > PNG_MAX_UINT || count == 0)
      ThrowReaderException(CorruptImageError,CorruptImage,image);
    chunk=(unsigned char *) NULL;
    p=NULL;
    if (length)
      {
        chunk=MagickAllocateMemory(unsigned char *,length);
        if (chunk == (unsigned char *) NULL)
          ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
            image);
        for (i=0; i < (long) length; i++)
          chunk[i]=ReadBlobByte(image);
        p=chunk;
      }
    (void) ReadBlobMSBLong(image);  /* read crc word */

    if (skip_to_iend)
      {
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_JHDR,4))
      {
        if (length == 16)
          {
            jng_width=(unsigned long) ((p[0] << 24) | (p[1] << 16) |
                (p[2] << 8) | p[3]);
            jng_height=(unsigned long) ((p[4] << 24) | (p[5] << 16) |
                (p[6] << 8) | p[7]);
            jng_color_type=p[8];
            jng_image_sample_depth=p[9];
            jng_image_compression_method=p[10];
            jng_image_interlace_method=p[11];
            jng_alpha_sample_depth=p[12];
            jng_alpha_compression_method=p[13];
            jng_alpha_filter_method=p[14];
            jng_alpha_interlace_method=p[15];
            if (logging)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_width:      %16lu",jng_width);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_width:      %16lu",jng_height);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_color_type: %16d",jng_color_type);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_image_sample_depth:      %3d",
                    jng_image_sample_depth);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_image_compression_method:%3d",
                    jng_image_compression_method);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_image_interlace_method:  %3d",
                    jng_image_interlace_method);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_alpha_sample_depth:      %3d",
                    jng_alpha_sample_depth);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_alpha_compression_method:%3d",
                    jng_alpha_compression_method);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_alpha_filter_method:     %3d",
                    jng_alpha_filter_method);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    jng_alpha_interlace_method:  %3d",
                    jng_alpha_interlace_method);
              }
          }
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }


    if (!reading_idat && !read_JSEP && (!memcmp(type,mng_JDAT,4) ||
        !memcmp(type,mng_JdAA,4) ||
        !memcmp(type,mng_IDAT,4) || !memcmp(type,mng_JDAA,4)))
      {
        /*
           o create color_image
           o open color_blob, attached to color_image
           o if (color type has alpha)
               open alpha_blob, attached to alpha_image
        */

        color_image_info=MagickAllocateMemory(ImageInfo *,sizeof(ImageInfo));
        if (color_image_info == (ImageInfo *) NULL)
          ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
              image);
        GetImageInfo(color_image_info);
        color_image=AllocateImage(color_image_info);
        if (color_image == (Image *) NULL)
          ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
              image);

        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Creating color_blob.");
        AcquireUniqueFilename(color_image->filename);
        status=OpenBlob(color_image_info,color_image,WriteBinaryBlobMode,
            exception);
        if (status == False)
            ThrowReaderException(CoderError,UnableToOpenBlob,color_image);

        if (!image_info->ping && jng_color_type >= 12)
          {
            alpha_image_info=MagickAllocateMemory(ImageInfo *,sizeof(ImageInfo));
            if (alpha_image_info == (ImageInfo *) NULL)
              ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
                  image);
            GetImageInfo(alpha_image_info);
            alpha_image=AllocateImage(alpha_image_info);
            if (alpha_image == (Image *) NULL)
              {
                DestroyImage(alpha_image);
                ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
                    alpha_image)
              }
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Creating alpha_blob.");
            AcquireUniqueFilename(alpha_image->filename);
            status=OpenBlob(alpha_image_info,alpha_image,WriteBinaryBlobMode,
                exception);
            if (status == False)
                ThrowReaderException(CoderError,UnableToOpenBlob,image);
            if (jng_alpha_compression_method == 0)
              {
                unsigned char
                  data[18];

                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Writing IHDR chunk to alpha_blob.");
                (void) WriteBlob(alpha_image,8,"\211PNG\r\n\032\n");
                (void) WriteBlobMSBULong(alpha_image,13L);
                PNGType(data,mng_IHDR);
                LogPNGChunk(logging,mng_IHDR,13L);
                PNGLong(data+4,jng_width);
                PNGLong(data+8,jng_height);
                data[12]=jng_alpha_sample_depth;
                data[13]=0; /* color_type gray */
                data[14]=0; /* compression method 0 */
                data[15]=0; /* filter_method 0 */
                data[16]=0; /* interlace_method 0 */
                (void) WriteBlob(alpha_image,17,data);
                (void) WriteBlobMSBULong(alpha_image,crc32(0,data,17));
              }
          }
        reading_idat=True;
      }

    if (!memcmp(type,mng_JDAT,4))
      {
        /*
           Copy chunk to color_image->blob
        */

        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Copying JDAT chunk data to color_blob.");

        (void) WriteBlob(color_image,length,(char *) chunk);
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_IDAT,4))
      {
        png_byte
           data[5];

        /*
           Copy IDAT header and chunk data to alpha_image->blob
        */

        if (!image_info->ping)
          {
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Copying IDAT chunk data to alpha_blob.");

            (void) WriteBlobMSBULong(alpha_image,(unsigned long) length);
            PNGType(data,mng_IDAT);
            LogPNGChunk(logging,mng_IDAT,length);
            (void) WriteBlob(alpha_image,4,(char *) data);
            (void) WriteBlob(alpha_image,length,(char *) chunk);
            (void) WriteBlobMSBULong(alpha_image,
                crc32(crc32(0,data,4),chunk,length));
          }
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_JDAA,4) || !memcmp(type,mng_JdAA,4))
      {
        /*
           Copy chunk data to alpha_image->blob
        */

        if (!image_info->ping)
          {
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Copying JDAA chunk data to alpha_blob.");

            (void) WriteBlob(alpha_image,length,(char *) chunk);
          }
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_JSEP,4))
      {
        read_JSEP=True;
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_bKGD,4))
      {
        if (length == 2)
          {
            image->background_color.red=ScaleCharToQuantum(p[1]);
            image->background_color.green=image->background_color.red;
            image->background_color.blue=image->background_color.red;
          }
        if (length == 6)
          {
            image->background_color.red=ScaleCharToQuantum(p[1]);
            image->background_color.green=ScaleCharToQuantum(p[3]);
            image->background_color.blue=ScaleCharToQuantum(p[5]);
          }
        MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_gAMA,4))
      {
        if (length == 4)
          image->gamma=((float) mng_get_long(p))*0.00001;
        MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_cHRM,4))
      {
        if (length == 32)
          {
            image->chromaticity.white_point.x=0.00001*mng_get_long(p);
            image->chromaticity.white_point.y=0.00001*mng_get_long(&p[4]);
            image->chromaticity.red_primary.x=0.00001*mng_get_long(&p[8]);
            image->chromaticity.red_primary.y=0.00001*mng_get_long(&p[12]);
            image->chromaticity.green_primary.x=0.00001*mng_get_long(&p[16]);
            image->chromaticity.green_primary.y=0.00001*mng_get_long(&p[20]);
            image->chromaticity.blue_primary.x=0.00001*mng_get_long(&p[24]);
            image->chromaticity.blue_primary.y=0.00001*mng_get_long(&p[28]);
          }
        MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_sRGB,4))
      {
        if (length == 1)
          {
            image->rendering_intent=(RenderingIntent) (p[0]+1);
            image->gamma=0.45455f;
            image->chromaticity.red_primary.x=0.6400f;
            image->chromaticity.red_primary.y=0.3300f;
            image->chromaticity.green_primary.x=0.3000f;
            image->chromaticity.green_primary.y=0.6000f;
            image->chromaticity.blue_primary.x=0.1500f;
            image->chromaticity.blue_primary.y=0.0600f;
            image->chromaticity.white_point.x=0.3127f;
            image->chromaticity.white_point.y=0.3290f;
          }
        MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_oFFs,4))
      {
        if (length > 8)
          {
            image->page.x=mng_get_long(p);
            image->page.y=mng_get_long(&p[4]);
            if ((int) p[9] != 0)
              {
                image->page.x/=10000;
                image->page.y/=10000;
              }
          }
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }

    if (!memcmp(type,mng_pHYs,4))
      {
        if (length > 8)
          {
            image->x_resolution=(double) mng_get_long(p);
            image->y_resolution=(double) mng_get_long(&p[4]);
            if ((int) p[8] == PNG_RESOLUTION_METER)
              {
                image->units=PixelsPerCentimeterResolution;
                image->x_resolution=image->x_resolution/100.0f;
                image->y_resolution=image->y_resolution/100.0f;
              }
          }
        MagickFreeMemory(chunk);
        continue;
      }

#if 0
    if (!memcmp(type,mng_iCCP,4))
      {
        /* To do. */
        if (length)
          MagickFreeMemory(chunk);
        continue;
      }
#endif

    if (length)
      MagickFreeMemory(chunk);

    if (memcmp(type,mng_IEND,4))
      continue;
    break;
  }


  /* IEND found */

  /*
    Finish up reading image data:

       o read main image from color_blob.

       o close color_blob.

       o if (color_type has alpha)
            if alpha_encoding is PNG
               read secondary image from alpha_blob via ReadPNG
            if alpha_encoding is JPEG
               read secondary image from alpha_blob via ReadJPEG

       o close alpha_blob.

       o copy intensity of secondary image into
         opacity samples of main image.

       o destroy the secondary image.
  */

  CloseBlob(color_image);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Reading jng_image from color_blob.");

  FormatString(color_image_info->filename,"%.1024s",color_image->filename);

  color_image_info->ping=False;   /* To do: avoid this */
  jng_image=ReadImage(color_image_info,exception);

  LiberateUniqueFileResource(color_image->filename);
  DestroyImage(color_image);
  DestroyImageInfo(color_image_info);

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Copying jng_image pixels to main image.");
  image->rows=jng_height;
  image->columns=jng_width;
  length=image->columns*sizeof(PixelPacket);
  for (y=0; y < (long) image->rows; y++)
  {
    s=AcquireImagePixels(jng_image,0,y,image->columns,1,&image->exception);
    q=GetImagePixels(image,0,y,image->columns,1);
    memcpy(q,s,length);
    if (!SyncImagePixels(image))
      break;
  }
  DestroyImage(jng_image);
  if (!image_info->ping)
    {
     if (jng_color_type >= 12)
       {
         if (jng_alpha_compression_method == 0)
           {
             png_byte
               data[5];
             (void) WriteBlobMSBULong(alpha_image,0x00000000L);
             PNGType(data,mng_IEND);
             LogPNGChunk(logging,mng_IEND,0L);
             (void) WriteBlob(alpha_image,4,(char *) data);
             (void) WriteBlobMSBULong(alpha_image,crc32(0,data,4));
           }
         CloseBlob(alpha_image);
         if (logging)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "    Reading opacity from alpha_blob.");

         FormatString(alpha_image_info->filename,"%.1024s",
             alpha_image->filename);

         jng_image=ReadImage(alpha_image_info,exception);

         for (y=0; y < (long) image->rows; y++)
         {
           s=AcquireImagePixels(jng_image,0,y,image->columns,1,
              &image->exception);
           q=GetImagePixels(image,0,y,image->columns,1);
           if (image->matte)
             for (x=(long) image->columns; x > 0; x--,q++,s++)
                q->opacity=(Quantum) MaxRGB-s->red;
           else
             for (x=(long) image->columns; x > 0; x--,q++,s++)
             {
                q->opacity=(Quantum) MaxRGB-s->red;
                if (q->opacity != OpaqueOpacity)
                  image->matte=True;
             }
           if (!SyncImagePixels(image))
             break;
         }
         LiberateUniqueFileResource(alpha_image->filename);
         DestroyImage(alpha_image);
         DestroyImageInfo(alpha_image_info);
         DestroyImage(jng_image);
       }
    }

  /*
    Read the JNG image.
  */
  image->page.width=jng_width;
  image->page.height=jng_height;
  image->page.x=mng_info->x_off[mng_info->object_id];
  image->page.y=mng_info->y_off[mng_info->object_id];
  mng_info->image_found++;
  (void) MagickMonitor(LoadImagesTag,2*GetBlobSize(image),2*GetBlobSize(image),
      exception);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  exit ReadOneJNGImage()");
  return (image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d J N G I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method ReadJNGImage reads a JPEG Network Graphics (JNG) image file
%  (including the 8-byte signature)  and returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  JNG support written by Glenn Randers-Pehrson, randeg@alum.rpi.edu.
%
%  The format of the ReadJNGImage method is:
%
%      Image *ReadJNGImage(const ImageInfo *image_info, ExceptionInfo
%         *exception)
%
%  A description of each parameter follows:
%
%    o image:  Method ReadJNGImage returns a pointer to the image after
%      reading.  A null image is returned if there is a memory shortage or
%      if the image cannot be read.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o exception: return any errors or warnings in this structure.
%
*/

static Image *ReadJNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  Image
    *image,
    *previous;

  MngInfo
    *mng_info;

  char
    magic_number[MaxTextExtent];

  int
    have_mng_structure,
    logging;

  unsigned int
    status;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter ReadJNGImage()");
  image=AllocateImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == False)
    ThrowReaderException(FileOpenError,UnableToOpenFile,image);
  if (LocaleCompare(image_info->magick,"JNG") != 0)
    ThrowReaderException(CorruptImageError,ImproperImageHeader,image);
  /*
    Verify JNG signature.
  */
  (void) ReadBlob(image,8,magic_number);
  if (memcmp(magic_number,"\213JNG\r\n\032\n",8) != 0)
    ThrowReaderException(CorruptImageError,ImproperImageHeader,image);
  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=False;
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  have_mng_structure=True;

  mng_info->image=image;
  previous=image;
  image=ReadOneJNGImage(mng_info,image_info,exception);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (image == (Image *) NULL)
    {
      CloseBlob(previous);
      DestroyImageList(previous);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "exit ReadJNGImage() with error");
      return((Image *) NULL);
    }
  CloseBlob(image);
  if (image->columns == 0 || image->rows == 0)
    {
      DestroyImageList(image);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "exit ReadJNGImage() with error");
      return((Image *) NULL);
    }
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadJNGImage()");
  return (image);
}
#endif

static Image *ReadMNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  char
    page_geometry[MaxTextExtent];

  Image
    *image,
    *previous;

  int
    have_mng_structure;

  volatile int
    first_mng_object,
    logging,
    object_id,
    term_chunk_found,
    skip_to_iend;

  volatile long
    image_count=0;

  MngInfo
    *mng_info;

  MngBox
    default_fb,
    fb,
    previous_fb;

#ifdef MNG_INSERT_LAYERS
  PixelPacket
    mng_background_color;
#endif

  register unsigned char
    *p;

  register long
    i;

  size_t
    count;

  short
    loop_level,
    loops_active;

  volatile short
    skipping_loop;

  unsigned int
#ifdef MNG_INSERT_LAYERS
    mandatory_back=0,
#endif
    status;

  volatile unsigned int
#ifdef MNG_OBJECT_BUFFERS
    mng_background_object=0,
#endif
    mng_type=0;   /* 0: PNG or JNG; 1: MNG; 2: MNG-LC; 3: MNG-VLC */

  unsigned long
    default_frame_timeout,
    frame_timeout,
#ifdef MNG_INSERT_LAYERS
    image_height,
    image_width,
#endif
    length;

  volatile unsigned long
    default_frame_delay,
    final_delay,
    final_image_delay,
    frame_delay,
#ifdef MNG_INSERT_LAYERS
    insert_layers,
#endif
    mng_iterations=1,
    simplicity=0,
    subframe_height=0,
    subframe_width=0;

  /*
    Set image_info->type=OptimizeType (new in version 5.4.0) to get the
    following optimizations:

    o  16-bit depth is reduced to 8 if all pixels contain samples whose
       high byte and low byte are identical.
    o  Opaque matte channel is removed.
    o  If matte channel is present but only one transparent color is
       present, RGB+tRNS is written instead of RGBA
    o  Grayscale images are reduced to 1, 2, or 4 bit depth if
       this can be done without loss.
    o  Palette is sorted to remove unused entries and to put a
       transparent color first, if PNG_SORT_PALETTE is also defined.
   */

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter ReadMNGImage()");
  image=AllocateImage(image_info);
  mng_info=(MngInfo *) NULL;
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == False)
    ThrowReaderException(FileOpenError,UnableToOpenFile,image);
  first_mng_object=False;
  skipping_loop=(-1);
  have_mng_structure=False;
  /*
    Allocate a MngInfo structure.
  */
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=True;
#if (QuantumDepth == 16)
    mng_info->optimize=image_info->type == OptimizeType;
#endif

  if (LocaleCompare(image_info->magick,"MNG") == 0)
    {
      char
        magic_number[MaxTextExtent];

      /*
        Verify MNG signature.
      */
      (void) ReadBlob(image,8,magic_number);
      if (memcmp(magic_number,"\212MNG\r\n\032\n",8) != 0)
        ThrowReaderException(CorruptImageError,ImproperImageHeader,image);
      /*
        Initialize some nonzero members of the MngInfo structure.
      */
      for (i=0; i < MNG_MAX_OBJECTS; i++)
      {
        mng_info->object_clip[i].right=PNG_MAX_UINT;
        mng_info->object_clip[i].bottom=PNG_MAX_UINT;
      }
      mng_info->exists[0]=True;
    }
  first_mng_object=True;
  mng_type=0;
#ifdef MNG_INSERT_LAYERS
  insert_layers=False;  /* should be False when converting or mogrifying */
#endif
  default_frame_delay=0;
  default_frame_timeout=0;
  frame_delay=0;
  final_delay=1;
  mng_info->ticks_per_second=100;
  object_id=0;
  skip_to_iend=False;
  term_chunk_found=False;
  mng_info->framing_mode=1;
#ifdef MNG_INSERT_LAYERS
  mandatory_back=False;
#endif
#ifdef MNG_INSERT_LAYERS
  mng_background_color=image->background_color;
#endif
  do
  {
    char
      type[MaxTextExtent];

    if (LocaleCompare(image_info->magick,"MNG") == 0)
      {
        unsigned char
          *chunk;

        /*
          Read a new chunk.
        */
        type[0]='\0';
        (void) strcat(type,"errr");
        length=ReadBlobMSBLong(image);
        count=ReadBlob(image,4,type);

        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Reading MNG chunk type %c%c%c%c, length: %lu",
             type[0],type[1],type[2],type[3],length);

        if (length > PNG_MAX_UINT)
          status=False;
        if (count == 0)
          ThrowReaderException(CorruptImageError,CorruptImage,image);
        p=NULL;
        chunk=(unsigned char *) NULL;
        if (length)
          {
            chunk=MagickAllocateMemory(unsigned char *,length);
            if (chunk == (unsigned char *) NULL)
              ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,
                image);
            for (i=0; i < (long) length; i++)
              chunk[i]=ReadBlobByte(image);
            p=chunk;
          }
        (void) ReadBlobMSBLong(image);  /* read crc word */

#if !defined(JNG_SUPPORTED)
        if (!memcmp(type,mng_JHDR,4))
          {
            skip_to_iend=True;
            if (!mng_info->jhdr_warning)
              (void) ThrowException(&image->exception,CoderError,JNGCompressionNotSupported,image->filename);
            mng_info->jhdr_warning++;
          }
#endif
        if (!memcmp(type,mng_DHDR,4))
          {
            skip_to_iend=True;
            if (!mng_info->dhdr_warning)
              (void) ThrowException(&image->exception,CoderError,DeltaPNGNotSupported,image->filename);
            mng_info->dhdr_warning++;
          }
        if (!memcmp(type,mng_MEND,4))
          break;
        if (skip_to_iend)
          {
            if (!memcmp(type,mng_IEND,4))
              skip_to_iend=False;
            if (length)
              MagickFreeMemory(chunk);
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Skip to IEND.");
            continue;
          }
        if (!memcmp(type,mng_MHDR,4))
          {
            mng_info->mng_width=(unsigned long) ((p[0] << 24) | (p[1] << 16) |
                (p[2] << 8) | p[3]);
            mng_info->mng_height=(unsigned long) ((p[4] << 24) | (p[5] << 16) |
                (p[6] << 8) | p[7]);
            if (logging)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  MNG width: %lu",mng_info->mng_width);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  MNG height: %lu",mng_info->mng_height);
              }
            p+=8;
            mng_info->ticks_per_second=mng_get_long(p);
            if (mng_info->ticks_per_second == 0)
              default_frame_delay=0;
            else
              default_frame_delay=100/mng_info->ticks_per_second;
            frame_delay=default_frame_delay;
            simplicity=0;
            if (length > 16)
              {
                p+=16;
                simplicity=mng_get_long(p);
              }
            mng_type=1;    /* Full MNG */
            if ((simplicity != 0) && ((simplicity | 11) == 11))
              mng_type=2; /* LC */
            if ((simplicity != 0) && ((simplicity | 9) == 9))
              mng_type=3; /* VLC */
#ifdef MNG_INSERT_LAYERS
            if (mng_type != 3 && !image_info->ping)
              insert_layers=True;
#endif
            if (GetPixels(image) != (PixelPacket *) NULL)
              {
                /*
                  Allocate next image structure.
                */
                AllocateNextImage(image_info,image);
                if (image->next == (Image *) NULL)
                  return((Image *) NULL);
                image=SyncNextImageInList(image);
                mng_info->image=image;
              }

            if ((mng_info->mng_width > 65535L) || (mng_info->mng_height
                 > 65535L))
              (void) ThrowException(&image->exception,ImageError,WidthOrHeightExceedsLimit,image->filename);
            FormatString(page_geometry,"%lux%lu+0+0",mng_info->mng_width,
                mng_info->mng_height);
            mng_info->frame.left=0;
            mng_info->frame.right=(long) mng_info->mng_width;
            mng_info->frame.top=0;
            mng_info->frame.bottom=(long) mng_info->mng_height;
            mng_info->clip=default_fb=previous_fb=mng_info->frame;
            for (i=0; i < MNG_MAX_OBJECTS; i++)
              mng_info->object_clip[i]=mng_info->frame;
            MagickFreeMemory(chunk);
            continue;
          }

        if (!memcmp(type,mng_TERM,4))
          {
            int
              repeat=0;


            if (length)
              repeat=p[0];
            if (repeat == 3)
              {
                final_delay=(png_uint_32) mng_get_long(&p[2]);
                mng_iterations=(png_uint_32) mng_get_long(&p[6]);
                if (mng_iterations == PNG_MAX_UINT)
                  mng_iterations=0;
                image->iterations=mng_iterations;
                term_chunk_found=True;
              }
            if (logging)
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    repeat=%d",repeat);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    final_delay=%ld",final_delay);
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    image->iterations=%ld",image->iterations);
              }
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_DEFI,4))
          {
            if (mng_type == 3)
              (void) ThrowException2(&image->exception,CoderError,
                "DEFI chunk found in MNG-VLC datastream",(char *) NULL);
            object_id=(p[0] << 8) | p[1];
            if (mng_type == 2 && object_id != 0)
              (void) ThrowException2(&image->exception,CoderError,
                "Nonzero object_id in MNG-LC datastream",(char *) NULL);
            if (object_id > MNG_MAX_OBJECTS)
              {
                /*
                  Instead of issuing a warning we should allocate a larger
                  MngInfo structure and continue.
                */
                (void) ThrowException2(&image->exception,CoderError,
                  "object id too large",(char *) NULL);
                object_id=MNG_MAX_OBJECTS;
              }
            if (mng_info->exists[object_id])
              if (mng_info->frozen[object_id])
                {
                  MagickFreeMemory(chunk);
                  (void) ThrowException2(&image->exception,CoderError,
                    "DEFI cannot redefine a frozen MNG object",(char *) NULL);
                  continue;
                }
            mng_info->exists[object_id]=True;
            if (length > 2)
              mng_info->invisible[object_id]=p[2];
            /*
              Extract object offset info.
            */
            if (length > 11)
              {
                mng_info->x_off[object_id]=(long) ((p[4] << 24) | (p[5] << 16) |
                (p[6] << 8) | p[7]);
                mng_info->y_off[object_id]=(long) ((p[8] << 24) | (p[9] << 16) |
                (p[10] << 8) | p[11]);
                if (logging)
                  {
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "  x_off[%d]: %lu",object_id,mng_info->x_off[object_id]);
                    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                        "  y_off[%d]: %lu",object_id,mng_info->y_off[object_id]);
                  }
              }
            /*
              Extract object clipping info.
            */
            if (length > 27)
              mng_info->object_clip[object_id]=mng_read_box(mng_info->frame,0,
                &p[12]);
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_bKGD,4))
          {
            mng_info->have_global_bkgd=False;
            if (length > 5)
              {
                mng_info->mng_global_bkgd.red
                    =ScaleShortToQuantum(((p[0] << 8) | p[1]));
                mng_info->mng_global_bkgd.green
                    =ScaleShortToQuantum(((p[2] << 8) | p[3]));
                mng_info->mng_global_bkgd.blue
                    =ScaleShortToQuantum(((p[4] << 8) | p[5]));
                mng_info->have_global_bkgd=True;
              }
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_BACK,4))
          {
#ifdef MNG_INSERT_LAYERS
            if (length > 6)
              mandatory_back=p[6];
            else
              mandatory_back=0;
            if (mandatory_back && length > 5)
              {
                mng_background_color.red=
                    ScaleShortToQuantum(((p[0] << 8) | p[1]));
                mng_background_color.green=
                    ScaleShortToQuantum(((p[2] << 8) | p[3]));
                mng_background_color.blue=
                    ScaleShortToQuantum(((p[4] << 8) | p[5]));
                mng_background_color.opacity=OpaqueOpacity;
              }
#ifdef MNG_OBJECT_BUFFERS
            if (length > 8)
              mng_background_object=(p[7] << 8) | p[8];
#endif
#endif
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_PLTE,4))
          {
            register long
             i;

            /*
              Read global PLTE.
            */
            if (length && (length < 769))
              {
                if (mng_info->global_plte == (png_colorp) NULL)
                  mng_info->global_plte=
                   MagickAllocateMemory(png_colorp,256*sizeof(png_color));
                for (i=0; i < (long) (length/3); i++)
                {
                  mng_info->global_plte[i].red=p[3*i];
                  mng_info->global_plte[i].green=p[3*i+1];
                  mng_info->global_plte[i].blue=p[3*i+2];
                }
                mng_info->global_plte_length=length/3;
              }
#ifdef MNG_LOOSE
            for ( ; i < 256; i++)
            {
              mng_info->global_plte[i].red=i;
              mng_info->global_plte[i].green=i;
              mng_info->global_plte[i].blue=i;
            }
            if (length)
              mng_info->global_plte_length=256;
#endif
            else
              mng_info->global_plte_length=0;
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_tRNS,4))
          {
            register long
              i;

            /* read global tRNS */

            if (length < 257)
              for (i=0; i < (long) length; i++)
                mng_info->global_trns[i]=p[i];

#ifdef MNG_LOOSE
            for ( ; i < 256; i++)
              mng_info->global_trns[i]=255;
#endif
            mng_info->global_trns_length=length;
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_gAMA,4))
          {
            if (length == 4)
              {
                long
                  igamma;

                igamma=mng_get_long(p);
                mng_info->global_gamma=((float) igamma)*0.00001;
                mng_info->have_global_gama=True;
              }
            else
              mng_info->have_global_gama=False;
            MagickFreeMemory(chunk);
            continue;
          }

        if (!memcmp(type,mng_cHRM,4))
          {
            /*
              Read global cHRM
            */
            if (length == 32)
              {
                mng_info->global_chrm.white_point.x=0.00001*mng_get_long(p);
                mng_info->global_chrm.white_point.y=0.00001*mng_get_long(&p[4]);
                mng_info->global_chrm.red_primary.x=0.00001*mng_get_long(&p[8]);
                mng_info->global_chrm.red_primary.y=0.00001*
                  mng_get_long(&p[12]);
                mng_info->global_chrm.green_primary.x=0.00001*
                  mng_get_long(&p[16]);
                mng_info->global_chrm.green_primary.y=0.00001*
                  mng_get_long(&p[20]);
                mng_info->global_chrm.blue_primary.x=0.00001*
                  mng_get_long(&p[24]);
                mng_info->global_chrm.blue_primary.y=0.00001*
                  mng_get_long(&p[28]);
                mng_info->have_global_chrm=True;
              }
            else
              mng_info->have_global_chrm=False;
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_sRGB,4))
          {
            /*
              Read global sRGB.
            */
            if (length)
              {
                mng_info->global_srgb_intent=(RenderingIntent) (p[0]+1);
                mng_info->have_global_srgb=True;
              }
            else
              mng_info->have_global_srgb=False;
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_iCCP,4))
          {
            /* To do. */

            /*
              Read global iCCP.
            */
            if (length)
              MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_FRAM,4))
          {
            if (mng_type == 3)
              (void) ThrowException2(&image->exception,CoderError,
                "FRAM chunk found in MNG-VLC datastream",(char *) NULL);
            if ((mng_info->framing_mode == 2) || (mng_info->framing_mode == 4))
              image->delay=frame_delay;
            frame_delay=default_frame_delay;
            frame_timeout=default_frame_timeout;
            fb=default_fb;
            if (length)
              if (p[0])
                mng_info->framing_mode=p[0];
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "    Framing_mode=%d",mng_info->framing_mode);
            if (length > 6)
              {
                /*
                  Note the delay and frame clipping boundaries.
                */
                p++; /* framing mode */
                while (*p && ((p-chunk) < (long) length))
                  p++;  /* frame name */
                p++;  /* frame name terminator */
                if ((p-chunk) < (long) (length-4))
                  {
                    int
                      change_delay,
                      change_timeout,
                      change_clipping;

                    change_delay=(*p++);
                    change_timeout=(*p++);
                    change_clipping=(*p++);
                    p++; /* change_sync */
                    if (change_delay)
                      {
                        frame_delay=(100*(mng_get_long(p))/
                            mng_info->ticks_per_second);
                        if (change_delay == 2)
                          default_frame_delay=frame_delay;
                        p+=4;
                        if (logging)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                              "    Framing_delay=%ld",frame_delay);
                      }
                    if (change_timeout)
                      {
                        frame_timeout=
                            (100*(mng_get_long(p))/mng_info->ticks_per_second);
                        if (change_delay == 2)
                          default_frame_timeout=frame_timeout;
                        p+=4;
                        if (logging)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                              "    Framing_timeout=%ld",frame_timeout);
                      }
                    if (change_clipping)
                      {
                        fb=mng_read_box(previous_fb,p[0],&p[1]);
                        p+=17;
                        previous_fb=fb;
                        if (logging)
                          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                              "    Frame_clipping: L=%ld R=%ld T=%ld B=%ld",
                              fb.left, fb.right,fb.top,fb.bottom);
                        if (change_clipping == 2)
                          default_fb=fb;
                      }
                  }
              }
            mng_info->clip=fb;
            mng_info->clip=mng_minimum_box(fb,mng_info->frame);
            subframe_width=(mng_info->clip.right-mng_info->clip.left);
            subframe_height=(mng_info->clip.bottom-mng_info->clip.top);
            /*
              Insert a background layer behind the frame if framing_mode is 4.
            */
#ifdef MNG_INSERT_LAYERS
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "   subframe_width=%lu, subframe_height=%lu",
                  subframe_width, subframe_height);
            if (insert_layers && (mng_info->framing_mode == 4) &&
                (subframe_width) && (subframe_height))
              {
                /*
                  Allocate next image structure.
                */
                if (GetPixels(image) != (PixelPacket *) NULL)
                  {
                    AllocateNextImage(image_info,image);
                    if (image->next == (Image *) NULL)
                      {
                        DestroyImageList(image);
                        MngInfoFreeStruct(mng_info,&have_mng_structure);
                        return((Image *) NULL);
                      }
                    image=SyncNextImageInList(image);
                  }
                mng_info->image=image;
                if (term_chunk_found)
                  {
                    image->start_loop=True;
                    image->iterations=mng_iterations;
                    term_chunk_found=False;
                  }
                else
                    image->start_loop=False;
                image->columns=subframe_width;
                image->rows=subframe_height;
                image->page.width=subframe_width;
                image->page.height=subframe_height;
                image->page.x=mng_info->clip.left;
                image->page.y=mng_info->clip.top;
                image->background_color=mng_background_color;
                image->matte=False;
                image->delay=0;
                SetImage(image,OpaqueOpacity);
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  Inserted background layer, L=%ld, R=%ld, T=%ld, B=%ld",
                      mng_info->clip.left,mng_info->clip.right,
                      mng_info->clip.top,mng_info->clip.bottom);
              }
#endif
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_CLIP,4))
          {
            unsigned int
              first_object,
              last_object;

            /*
              Read CLIP.
            */
            first_object=(p[0] << 8) | p[1];
            last_object=(p[2] << 8) | p[3];
            for (i=(int) first_object; i <= (int) last_object; i++)
            {
              if (mng_info->exists[i] && !mng_info->frozen[i])
                {
                  MngBox
                    box;

                  box=mng_info->object_clip[i];
                  mng_info->object_clip[i]=mng_read_box(box,p[4],&p[5]);
                }
            }
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_SAVE,4))
          {
            register long
              i;

            for (i=1; i < MNG_MAX_OBJECTS; i++)
              if (mng_info->exists[i])
                {
                 mng_info->frozen[i]=True;
#ifdef MNG_OBJECT_BUFFERS
                 if (mng_info->ob[i] != (MngBuffer *) NULL)
                    mng_info->ob[i]->frozen=True;
#endif
                }
            if (length)
              MagickFreeMemory(chunk);
            continue;
          }

        if (!memcmp(type,mng_DISC,4) || !memcmp(type,mng_SEEK,4))
          {
            register long
              i;

            /*
              Read DISC or SEEK.
            */
            if ((length == 0) || !memcmp(type,mng_SEEK,4))
              {
                for (i=1; i < MNG_MAX_OBJECTS; i++)
                  MngInfoDiscardObject(mng_info,i);
              }
            else
              {
                register long
                  j;

                for (j=0; j < (long) length; j+=2)
                {
                  i=p[j] << 8 | p[j+1];
                  MngInfoDiscardObject(mng_info,i);
                }
              }
            if (length)
              MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_MOVE,4))
          {
            unsigned long
              first_object,
              last_object;

            /*
              read MOVE
            */
            first_object=(p[0] << 8) | p[1];
            last_object=(p[2] << 8) | p[3];
            for (i=(long) first_object; i <= (long) last_object; i++)
            {
              if (mng_info->exists[i] && !mng_info->frozen[i])
                {
                  MngPair
                    new_pair;

                  MngPair
                    old_pair;

                  old_pair.a=mng_info->x_off[i];
                  old_pair.b=mng_info->y_off[i];
                  new_pair=mng_read_pair(old_pair,(int) p[4],&p[5]);
                  mng_info->x_off[i]=new_pair.a;
                  mng_info->y_off[i]=new_pair.b;
                }
            }
            MagickFreeMemory(chunk);
            continue;
          }

        if (!memcmp(type,mng_LOOP,4))
          {
            long loop_iters=1;
            loop_level=chunk[0];
            loops_active++;
            mng_info->loop_active[loop_level]=1;  /* mark loop active */
            /*
              Record starting point.
            */
            loop_iters=mng_get_long(&chunk[1]);
            if (loop_iters == 0)
              skipping_loop=loop_level;
            else
              {
                mng_info->loop_jump[loop_level]=TellBlob(image);
                mng_info->loop_count[loop_level]=loop_iters;
              }
            mng_info->loop_iteration[loop_level]=0;
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_ENDL,4))
          {
            loop_level=chunk[0];
            if (skipping_loop > 0)
              {
                if (skipping_loop == loop_level)
                  {
                    /*
                      Found end of zero-iteration loop.
                    */
                    skipping_loop=(-1);
                    loops_active--;
                    mng_info->loop_active[loop_level]=0;
                  }
              }
            else
              {
                if (mng_info->loop_active[loop_level] == 1)
                  {
                    mng_info->loop_count[loop_level]--;
                    mng_info->loop_iteration[loop_level]++;
                    if (mng_info->loop_count[loop_level] != 0)
                      (void) SeekBlob(image,mng_info->loop_jump[loop_level],
                        SEEK_SET);
                    else
                      {
                        short
                          last_level;

                        /*
                          Finished loop.
                        */
                        loops_active--;
                        mng_info->loop_active[loop_level]=0;
                        last_level=(-1);
                        for (i=0; i < loop_level; i++)
                          if (mng_info->loop_active[i] == 1)
                            last_level=(short) i;
                        loop_level=last_level;
                      }
                  }
              }
            MagickFreeMemory(chunk);
            continue;
          }
        if (!memcmp(type,mng_CLON,4))
          {
            if (!mng_info->clon_warning)
              (void) ThrowException2(&image->exception,CoderError,
                "CLON is not implemented yet",image->filename);
            mng_info->clon_warning++;
          }
        if (!memcmp(type,mng_MAGN,4))
          {
            png_uint_16
              magn_first,
              magn_last,
              magn_mb,
              magn_ml,
              magn_mr,
              magn_mt,
              magn_mx,
              magn_my,
              magn_methx,
              magn_methy;

            if (length > 1)
              magn_first=(p[0] << 8) | p[1];
            else
              magn_first=0;
            if (length > 3)
              magn_last=(p[2] << 8) | p[3];
            else
              magn_last=magn_first;
#ifndef MNG_OBJECT_BUFFERS
            if (magn_first || magn_last)
              if (!mng_info->magn_warning)
                {
                  (void) ThrowException2(&image->exception,CoderError,
                     "MAGN is not implemented yet for nonzero objects",
                     image->filename);
                   mng_info->magn_warning++;
                }
#endif
            if (length > 4)
              magn_methx=p[4];
            else
              magn_methx=0;

            if (length > 6)
              magn_mx=(p[5] << 8) | p[6];
            else
              magn_mx=1;
            if (magn_mx == 0)
              magn_mx=1;

            if (length > 8)
              magn_my=(p[7] << 8) | p[8];
            else
              magn_my=magn_mx;
            if (magn_my == 0)
              magn_my=1;

            if (length > 10)
              magn_ml=(p[9] << 8) | p[10];
            else
              magn_ml=magn_mx;
            if (magn_ml == 0)
              magn_ml=1;

            if (length > 12)
              magn_mr=(p[11] << 8) | p[12];
            else
              magn_mr=magn_mx;
            if (magn_mr == 0)
              magn_mr=1;

            if (length > 14)
              magn_mt=(p[13] << 8) | p[14];
            else
              magn_mt=magn_my;
            if (magn_mt == 0)
              magn_mt=1;

            if (length > 16)
              magn_mb=(p[15] << 8) | p[16];
            else
              magn_mb=magn_my;
            if (magn_mb == 0)
              magn_mb=1;

            if (length > 17)
              magn_methy=p[17];
            else
              magn_methy=magn_methx;

            if (magn_methx > 5 || magn_methy > 5)
              if (!mng_info->magn_warning)
                {
                  (void) ThrowException2(&image->exception,CoderError,
                     "Unknown MAGN method in MNG datastream",image->filename);
                   mng_info->magn_warning++;
                }
#ifdef MNG_OBJECT_BUFFERS
          /* Magnify existing objects in the range magn_first to magn_last */
#endif
            if (magn_first == 0 || magn_last == 0)
              {
                /* Save the magnification factors for object 0 */
                mng_info->magn_mb=magn_mb;
                mng_info->magn_ml=magn_ml;
                mng_info->magn_mr=magn_mr;
                mng_info->magn_mt=magn_mt;
                mng_info->magn_mx=magn_mx;
                mng_info->magn_my=magn_my;
                mng_info->magn_methx=magn_methx;
                mng_info->magn_methy=magn_methy;
              }
          }
        if (!memcmp(type,mng_PAST,4))
          {
            if (!mng_info->past_warning)
              (void) ThrowException2(&image->exception,CoderError,
                "PAST is not implemented yet",image->filename);
            mng_info->past_warning++;
          }
        if (!memcmp(type,mng_SHOW,4))
          {
            if (!mng_info->show_warning)
              (void) ThrowException2(&image->exception,CoderError,
                "SHOW is not implemented yet",image->filename);
            mng_info->show_warning++;
          }
        if (!memcmp(type,mng_sBIT,4))
          {
            if (length < 4)
              mng_info->have_global_sbit=False;
            else
              {
                mng_info->global_sbit.gray=p[0];
                mng_info->global_sbit.red=p[0];
                mng_info->global_sbit.green=p[1];
                mng_info->global_sbit.blue=p[2];
                mng_info->global_sbit.alpha=p[3];
                mng_info->have_global_sbit=True;
             }
          }
        if (!memcmp(type,mng_pHYs,4))
          {
            if (length > 8)
              {
                mng_info->global_x_pixels_per_unit=mng_get_long(p);
                mng_info->global_y_pixels_per_unit=mng_get_long(&p[4]);
                mng_info->global_phys_unit_type=p[8];
                mng_info->have_global_phys=True;
              }
            else
              mng_info->have_global_phys=False;
          }
        if (!memcmp(type,mng_pHYg,4))
          {
            if (!mng_info->phyg_warning)
              (void) ThrowException2(&image->exception,CoderError,
                "pHYg is not implemented.",image->filename);
            mng_info->phyg_warning++;
          }
        if (!memcmp(type,mng_BASI,4))
          {
            skip_to_iend=True;
            if (!mng_info->basi_warning)
              (void) ThrowException2(&image->exception,CoderError,
                "BASI is not implemented yet",image->filename);
            mng_info->basi_warning++;
#ifdef MNG_BASI_SUPPORTED
            basi_width=(unsigned long) ((p[0] << 24) | (p[1] << 16) |
               (p[2] << 8) | p[3]);
            basi_height=(unsigned long) ((p[4] << 24) | (p[5] << 16) |
               (p[6] << 8) | p[7]);
            basi_color_type=p[8];
            basi_compression_method=p[9];
            basi_filter_type=p[10];
            basi_interlace_method=p[11];
            if (length > 11)
              basi_red=(p[12] << 8) & p[13];
            else
              basi_red=0;
            if (length > 13)
              basi_green=(p[14] << 8) & p[15];
            else
              basi_green=0;
            if (length > 15)
              basi_blue=(p[16] << 8) & p[17];
            else
              basi_blue=0;
            if (length > 17)
              basi_alpha=(p[18] << 8) & p[19];
            else
              {
                if (basi_sample_depth == 16)
                  basi_alpha=65535L;
                else
                  basi_alpha=255;
              }
            if (length > 19)
              basi_viewable=p[20];
            else
              basi_viewable=0;
#endif
            MagickFreeMemory(chunk);
            continue;
          }
        if (memcmp(type,mng_IHDR,4)
#if defined(JNG_SUPPORTED)
            && memcmp(type,mng_JHDR,4)
#endif
            )
          {
            /* Not an IHDR or JHDR chunk */
            if (length)
              MagickFreeMemory(chunk);
            continue;
          }
/* Process IHDR */
        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Processing %c%c%c%c chunk",type[0],type[1],type[2],type[3]);
        mng_info->exists[object_id]=True;
        mng_info->viewable[object_id]=True;
        if (mng_info->invisible[object_id])
          {
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Skipping invisible object");
            skip_to_iend=True;
            MagickFreeMemory(chunk);
            continue;
          }
#ifdef MNG_INSERT_LAYERS
        if (length < 8)
          ThrowReaderException(CorruptImageError,ImproperImageHeader,image);
        image_width=mng_get_long(p);
        image_height=mng_get_long(&p[4]);
#endif
        MagickFreeMemory(chunk);

        /*
          Insert a transparent background layer behind the entire animation
          if it is not full screen.
        */
#ifdef MNG_INSERT_LAYERS
        if (insert_layers && mng_type && first_mng_object)
          {
            if ((mng_info->clip.left > 0) || (mng_info->clip.top > 0) ||
                (image_width < mng_info->mng_width) ||
                (mng_info->clip.right < (long) mng_info->mng_width) ||
                (image_height < mng_info->mng_height) ||
                (mng_info->clip.bottom < (long) mng_info->mng_height))
              {
                if (GetPixels(image) != (PixelPacket *) NULL)
                  {
                    /*
                      Allocate next image structure.
                    */
                    AllocateNextImage(image_info,image);
                    if (image->next == (Image *) NULL)
                      {
                        DestroyImageList(image);
                        MngInfoFreeStruct(mng_info,&have_mng_structure);
                        return((Image *) NULL);
                      }
                    image=SyncNextImageInList(image);
                  }
                mng_info->image=image;
                if (term_chunk_found)
                  {
                    image->start_loop=True;
                    image->iterations=mng_iterations;
                    term_chunk_found=False;
                  }
                else
                    image->start_loop=False;
                /*
                  Make a background rectangle.
                */
                image->delay=0;
                image->columns=mng_info->mng_width;
                image->rows=mng_info->mng_height;
                image->page.width=mng_info->mng_width;
                image->page.height=mng_info->mng_height;
                image->page.x=0;
                image->page.y=0;
                image->background_color=mng_background_color;
                SetImage(image,TransparentOpacity);
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  Inserted transparent background layer, W=%lud, H=%lud",
                      mng_info->mng_width,mng_info->mng_height);
              }
          }
        /*
          Insert a background layer behind the upcoming image if
          framing_mode is 3, and we haven't already inserted one.
        */
        if (insert_layers && (mng_info->framing_mode == 3) &&
                (subframe_width) && (subframe_height) && (simplicity == 0 ||
                (simplicity & 0x08)))
          {
            if (GetPixels(image) != (PixelPacket *) NULL)
            {
              /*
                Allocate next image structure.
              */
              AllocateNextImage(image_info,image);
              if (image->next == (Image *) NULL)
                {
                  DestroyImageList(image);
                  MngInfoFreeStruct(mng_info,&have_mng_structure);
                  return((Image *) NULL);
                }
              image=SyncNextImageInList(image);
            }
            mng_info->image=image;
            if (term_chunk_found)
              {
                image->start_loop=True;
                image->iterations=mng_iterations;
                term_chunk_found=False;
              }
            else
                image->start_loop=False;
            image->delay=0;
            image->columns=subframe_width;
            image->rows=subframe_height;
            image->page.width=subframe_width;
            image->page.height=subframe_height;
            image->page.x=mng_info->clip.left;
            image->page.y=mng_info->clip.top;
            image->background_color=mng_background_color;
            image->matte=False;
            SetImage(image,OpaqueOpacity);
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Inserted background layer, L=%ld, R=%ld, T=%ld, B=%ld",
                  mng_info->clip.left,mng_info->clip.right,
                  mng_info->clip.top,mng_info->clip.bottom);
          }
#endif /* MNG_INSERT_LAYERS */
        first_mng_object=False;
        if (GetPixels(image) != (PixelPacket *) NULL)
          {
            /*
              Allocate next image structure.
            */
            AllocateNextImage(image_info,image);
            if (image->next == (Image *) NULL)
              {
                DestroyImageList(image);
                MngInfoFreeStruct(mng_info,&have_mng_structure);
                return((Image *) NULL);
              }
            image=SyncNextImageInList(image);
          }
        mng_info->image=image;
        if (!MagickMonitor(LoadImagesTag,TellBlob(image),GetBlobSize(image),
            exception))
          break;
        if (term_chunk_found)
          {
            image->start_loop=True;
            term_chunk_found=False;
          }
        else
            image->start_loop=False;
        if (mng_info->framing_mode == 1 || mng_info->framing_mode == 3)
          {
            image->delay=frame_delay;
            frame_delay=default_frame_delay;
          }
        else
          image->delay=0;
        image->page.width=mng_info->mng_width;
        image->page.height=mng_info->mng_height;
        image->page.x=mng_info->x_off[object_id];
        image->page.y=mng_info->y_off[object_id];
        image->iterations=mng_iterations;
        /*
          Seek back to the beginning of the IHDR or JHDR chunk's length field.
        */
        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Seeking back to beginning of %c%c%c%c chunk",type[0],type[1],
              type[2],type[3]);
        (void) SeekBlob(image,-((long) length+12),SEEK_CUR);
      }

    previous=image;
    mng_info->image=image;
    mng_info->mng_type=mng_type;
    mng_info->object_id=object_id;

    if (!memcmp(type,mng_IHDR,4))
      image=ReadOnePNGImage(mng_info,image_info,exception);
#if defined(JNG_SUPPORTED)
    else
      image=ReadOneJNGImage(mng_info,image_info,exception);
#endif

    if (image == (Image *) NULL)
      {
        DestroyImageList(previous);
        CloseBlob(previous);
        MngInfoFreeStruct(mng_info,&have_mng_structure);
        return((Image *) NULL);
      }
    if (image->columns == 0 || image->rows == 0)
      {
        CloseBlob(image);
        DestroyImageList(image);
        MngInfoFreeStruct(mng_info,&have_mng_structure);
        return((Image *) NULL);
      }
    mng_info->image=image;

    if (mng_type)
      {
        MngBox
          crop_box;

        if (mng_info->magn_methx || mng_info->magn_methy)
          {
            png_uint_32
               magnified_height,
               magnified_width;

            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Processing MNG MAGN chunk");

            if (mng_info->magn_methx == 1)
              {
                magnified_width=mng_info->magn_ml;
                if (image->columns > 1)
                   magnified_width += mng_info->magn_mr;
                if (image->columns > 2)
                   magnified_width += (image->columns-2)*(mng_info->magn_mx);
              }
            else
              {
                magnified_width=image->columns;
                if (image->columns > 1)
                   magnified_width += mng_info->magn_ml-1;
                if (image->columns > 2)
                   magnified_width += mng_info->magn_mr-1;
                if (image->columns > 3)
                   magnified_width += (image->columns-3)*(mng_info->magn_mx-1);
              }
            if (mng_info->magn_methy == 1)
              {
                magnified_height=mng_info->magn_mt;
                if (image->rows > 1)
                   magnified_height += mng_info->magn_mb;
                if (image->rows > 2)
                   magnified_height += (image->rows-2)*(mng_info->magn_my);
              }
            else
              {
                magnified_height=image->rows;
                if (image->rows > 1)
                   magnified_height += mng_info->magn_mt-1;
                if (image->rows > 2)
                   magnified_height += mng_info->magn_mb-1;
                if (image->rows > 3)
                   magnified_height += (image->rows-3)*(mng_info->magn_my-1);
              }
            if (magnified_height > image->rows ||
                magnified_width > image->columns)
              {
                Image
                  *large_image;

                int
                  yy;

                long
                  m,
                  y;

                register long
                  i,
                  x;

                register PixelPacket
                  *n,
                  *p,
                  *q;

                PixelPacket
                  *next,
                  *prev;

                size_t
                  length;

                png_uint_16
                  magn_methx,
                  magn_methy;

                /*
                  Allocate next image structure.
                */
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Allocate magnified image");
                AllocateNextImage(image_info,image);
                if (image->next == (Image *) NULL)
                  {
                    DestroyImageList(image);
                    MngInfoFreeStruct(mng_info,&have_mng_structure);
                    return((Image *) NULL);
                  }

                large_image=SyncNextImageInList(image);

                large_image->columns=magnified_width;
                large_image->rows=magnified_height;

                magn_methx=mng_info->magn_methx;
                magn_methy=mng_info->magn_methy;

#if (QuantumDepth == 32)
#define QM unsigned short
                if (magn_methx != 1 || magn_methy != 1)
                  {
                  /*
                     Scale pixels to unsigned shorts to prevent
                     overflow of intermediate values of interpolations
                  */
                     for (y=0; y < (long) image->rows; y++)
                     {
                       q=GetImagePixels(image,0,y,image->columns,1);
                       for (x=(long) image->columns; x > 0; x--)
                       {
                          q->red=ScaleQuantumToShort(q->red);
                          q->green=ScaleQuantumToShort(q->green);
                          q->blue=ScaleQuantumToShort(q->blue);
                          q->opacity=ScaleQuantumToShort(q->opacity);
                          q++;
                       }
                       if (!SyncImagePixels(image))
                         break;
                     }
                  }
#else
#define QM Quantum
#endif

                if (image->matte)
                   SetImage(large_image,TransparentOpacity);
                else
                  {
                    large_image->background_color.opacity=OpaqueOpacity;
                    SetImage(large_image,OpaqueOpacity);
                    if (magn_methx == 4)
                      magn_methx=2;
                    if (magn_methx == 5)
                      magn_methx=3;
                    if (magn_methy == 4)
                      magn_methy=2;
                    if (magn_methy == 5)
                      magn_methy=3;
                  }

                /* magnify the rows into the right side of the large image */

                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Magnify the rows to %lu",large_image->rows);
                m=mng_info->magn_mt;
                yy=0;
                length=(size_t) (image->columns*sizeof(PixelPacket));
                next=MagickAllocateMemory(PixelPacket *,length);
                prev=MagickAllocateMemory(PixelPacket *,length);
                if ((prev == (PixelPacket *) NULL) ||
                    (next == (PixelPacket *) NULL))
                  {
                     DestroyImageList(image);
                     MngInfoFreeStruct(mng_info,&have_mng_structure);
                     ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image)
                  }
                n=GetImagePixels(image,0,0,image->columns,1);
                (void) memcpy(next,n,length);
                for (y=0; y < (long) image->rows; y++)
                {
                  if (y == 0)
                    m=mng_info->magn_mt;
                  else if (magn_methy > 1 && y == (long) image->rows-2)
                    m=mng_info->magn_mb;
                  else if (magn_methy <= 1 && y == (long) image->rows-1)
                    m=mng_info->magn_mb;
                  else if (magn_methy > 1 && y == (long) image->rows-1)
                    m=1;
                  else
                    m=mng_info->magn_my;
                  n=prev;
                  prev=next;
                  next=n;
                  if (y < (long) image->rows-1)
                    {
                      n=GetImagePixels(image,0,y+1,image->columns,1);
                      (void) memcpy(next,n,length);
                    }
                  for (i=0; i < m; i++, yy++)
                  {
                    assert(yy < (long) large_image->rows);
                    p=prev;
                    n=next;
                    q=SetImagePixels(large_image,0,yy,large_image->columns,1);
                    q+=(large_image->columns-image->columns);
                    for (x=(long) image->columns; x > 0; x--)
                    {
                      /* TO DO: get color as function of indexes[x] */
                      /*
                      if (image->storage_class == PseudoClass)
                        {
                        }
                      */

                      if (magn_methy <= 1)
                        {
                          *q=(*p); /* replicate previous */
                        }
                      else if (magn_methy == 2 || magn_methy == 4)
                        {
                          if (i == 0)
                             *q=(*p);
                          else
                            {
                              /* Interpolate */
                              (*q).red=(QM) (((long) (2*i*((*n).red
                                 -(*p).red)+m))/((long) (m*2))+(*p).red);
                              (*q).green=(QM) (((long) (2*i*((*n).green
                                 -(*p).green)+m))/((long) (m*2))+(*p).green);
                              (*q).blue=(QM) (((long) (2*i*((*n).blue
                                 -(*p).blue)+m))/((long) (m*2))+(*p).blue);
                              if (image->matte)
                                 (*q).opacity=(QM) (((long)
                                 (2*i*((*n).opacity-(*p).opacity)+m))
                                 /((long) (m*2))+(*p).opacity);
                            }
                          if (magn_methy == 4)
                            {
                              /* Replicate nearest */
                              if (i <= ((m+1) << 1))
                                 (*q).opacity=(*p).opacity+0;
                              else
                                 (*q).opacity=(*n).opacity+0;
                            }
                        }
                      else /* if (magn_methy == 3 || magn_methy == 5) */
                        {
                          /* Replicate nearest */
                          if (i <= ((m+1) << 1))
                             *q=(*p);
                          else
                             *q=(*n);
                          if (magn_methy == 5)
                            {
                              (*q).opacity=(QM) (((long) (2*i*((*n).opacity
                                 -(*p).opacity)+m))/((long) (m*2))+(*p).opacity);
                            }
                        }
                      n++;
                      q++;
                      p++;
                    } /* x */
                    if (!SyncImagePixels(large_image))
                      break;
                  } /* i */
                } /* y */
                MagickFreeMemory(prev);
                MagickFreeMemory(next);

                length=image->columns;

                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Delete original image");

                DeleteImageFromList(&image);

                image=large_image;

                mng_info->image=image;

                /* magnify the columns */
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Magnify the columns to %lu",image->columns);

                for (y=0; y < (long) image->rows; y++)
                {
                  q=GetImagePixels(image,0,y,image->columns,1);
                  p=q+(image->columns-length);
                  n=p+1;
                  for (x=(long) (image->columns-length);
                    x < (long) image->columns; x++)
                  {
                    if (x == (long) (image->columns-length))
                      m=mng_info->magn_ml;
                    else if (magn_methx > 1 && x == (long) image->columns-2)
                      m=mng_info->magn_mr;
                    else if (magn_methx <= 1 && x == (long) image->columns-1)
                      m=mng_info->magn_mr;
                    else if (magn_methx > 1 && x == (long) image->columns-1)
                      m=1;
                    else
                      m=mng_info->magn_mx;
                    for (i=0; i < m; i++)
                    {
                      if (magn_methx <= 1)
                        {
                          /* replicate previous */
                          *q=(*p);
                        }
                      else if (magn_methx == 2 || magn_methx == 4)
                        {
                          if (i == 0)
                            *q=(*p);
                          else
                            {
                              /* Interpolate */
                              (*q).red=(QM) ((2*i*((*n).red-(*p).red)+m)
                                 /((long) (m*2))+(*p).red);
                              (*q).green=(QM) ((2*i*((*n).green-(*p).green)
                                 +m)/((long) (m*2))+(*p).green);
                              (*q).blue=(QM) ((2*i*((*n).blue-(*p).blue)+m)
                                 /((long) (m*2))+(*p).blue);
                              if (image->matte)
                                 (*q).opacity=(QM) ((2*i*((*n).opacity
                                   -(*p).opacity)+m)/((long) (m*2))
                                   +(*p).opacity);
                            }
                          if (magn_methx == 4)
                            {
                              /* Replicate nearest */
                              if (i <= ((m+1) << 1))
                                 (*q).opacity=(*p).opacity+0;
                              else
                                 (*q).opacity=(*n).opacity+0;
                            }
                        }
                      else /* if (magn_methx == 3 || magn_methx == 5) */
                        {
                          /* Replicate nearest */
                          if (i <= ((m+1) << 1))
                             *q=(*p);
                          else
                             *q=(*n);
                          if (magn_methx == 5)
                            {
                              /* Interpolate */
                              (*q).opacity=(QM) ((2*i*((*n).opacity
                                 -(*p).opacity)+m) /((long) (m*2))
                                 +(*p).opacity);
                            }
                        }
                      q++;
                    }
                    n++;
                    p++;
                  }
                  if (!SyncImagePixels(image))
                    break;
                }
#if (QuantumDepth == 32)
              if (magn_methx != 1 || magn_methy != 1)
                {
                /*
                   Rescale pixels to Quantum
                */
                   for (y=0; y < (long) image->rows; y++)
                   {
                     q=GetImagePixels(image,0,y,image->columns,1);
                     for (x=(long) image->columns; x > 0; x--)
                     {
                        q->red=ScaleShortToQuantum(q->red);
                        q->green=ScaleShortToQuantum(q->green);
                        q->blue=ScaleShortToQuantum(q->blue);
                        q->opacity=ScaleShortToQuantum(q->opacity);
                        q++;
                     }
                     if (!SyncImagePixels(image))
                       break;
                   }
                }
#endif
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  Finished MAGN processing");
              }
          }

        /*
          Crop_box is with respect to the upper left corner of the MNG.
        */
        crop_box.left=mng_info->image_box.left+mng_info->x_off[object_id];
        crop_box.right=mng_info->image_box.right+mng_info->x_off[object_id];
        crop_box.top=mng_info->image_box.top+mng_info->y_off[object_id];
        crop_box.bottom=mng_info->image_box.bottom+mng_info->y_off[object_id];
        crop_box=mng_minimum_box(crop_box,mng_info->clip);
        crop_box=mng_minimum_box(crop_box,mng_info->frame);
        crop_box=mng_minimum_box(crop_box,mng_info->object_clip[object_id]);
        if ((crop_box.left != (mng_info->image_box.left
            +mng_info->x_off[object_id])) ||
            (crop_box.right != (mng_info->image_box.right
            +mng_info->x_off[object_id])) ||
            (crop_box.top != (mng_info->image_box.top
            +mng_info->y_off[object_id])) ||
            (crop_box.bottom != (mng_info->image_box.bottom
            +mng_info->y_off[object_id])))
          {
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Crop the PNG image");
            if ((crop_box.left < crop_box.right) &&
                (crop_box.top < crop_box.bottom))
              {
                Image
                  *p;

                RectangleInfo
                  crop_info;

                /*
                  Crop_info is with respect to the upper left corner of
                  the image.
                */
                crop_info.x=(crop_box.left-mng_info->x_off[object_id]);
                crop_info.y=(crop_box.top-mng_info->y_off[object_id]);
                crop_info.width=(crop_box.right-crop_box.left);
                crop_info.height=(crop_box.bottom-crop_box.top);
                image->page.width=image->columns;
                image->page.height=image->rows;
                image->page.x=0;
                image->page.y=0;
                p=CropImage(image,&crop_info,exception);
                if (p != (Image *) NULL)
                  {
                    image->columns=p->columns;
                    image->rows=p->rows;
                    DestroyImage(p);
                    image->page.width=image->columns;
                    image->page.height=image->rows;
                    image->page.x=crop_box.left;
                    image->page.y=crop_box.top;
                  }
              }
            else
              {
                /*
                  No pixels in crop area.  The MNG spec still requires
                  a layer, though, so make a single transparent pixel in
                  the top left corner.
                */
                image->columns=1;
                image->rows=1;
                image->colors=2;
                SetImage(image,TransparentOpacity);
                image->page.width=1;
                image->page.height=1;
                image->page.x=0;
                image->page.y=0;
              }
          }
#ifndef PNG_READ_EMPTY_PLTE_SUPPORTED
        image=mng_info->image;
#endif
      }

#if (QuantumDepth == 16)  /* TO DO: treat Q:32 */
    /* Determine if bit depth can be reduced from 16 to 8.
     * Note that the method GetImageDepth doesn't check background
     * and doesn't handle PseudoClass specially.  Also it uses
     * multiplication and division by 257 instead of shifting, so
     * might be slower.
     */
    if (mng_info->optimize && image->depth == 16)
      {
        int
          ok_to_reduce;

        const PixelPacket
          *p;

        ok_to_reduce=((((image->background_color.red >> 8) & 0xff)
          == (image->background_color.red & 0xff)) &&
           (((image->background_color.green >> 8) & 0xff)
          == (image->background_color.green & 0xff)) &&
           (((image->background_color.blue >> 8) & 0xff)
          == (image->background_color.blue & 0xff)));
        if (ok_to_reduce && image->storage_class == PseudoClass)
          {
            int index;

            for (index=0; index < (long) image->colors; index++)
              {
                ok_to_reduce=((((image->colormap[index].red >> 8) & 0xff)
                  == (image->colormap[index].red & 0xff)) &&
                  (((image->colormap[index].green >> 8) & 0xff)
                  == (image->colormap[index].green & 0xff)) &&
                  (((image->colormap[index].blue >> 8) & 0xff)
                  == (image->colormap[index].blue & 0xff)));
                if (!ok_to_reduce)
                  break;
              }
          }
        if (ok_to_reduce && image->storage_class != PseudoClass)
          {
            long
              y;

            register long
              x;

            for (y=0; y < (long) image->rows; y++)
            {
              p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
              if (p == (const PixelPacket *) NULL)
                break;
              for (x=(long) image->columns; x > 0; x--)
              {
                ok_to_reduce=((((p->red >> 8) & 0xff) == (p->red & 0xff)) &&
                  (((p->green >> 8) & 0xff) == (p->green & 0xff)) &&
                  (((p->blue >> 8) & 0xff) == (p->blue & 0xff)) &&
                  (((!image->matte ||
                  ((p->opacity >> 8) & 0xff) == (p->opacity & 0xff)))));
                if (!ok_to_reduce)
                  break;
                p++;
              }
              if (x != 0)
                break;
            }
          }
        if (ok_to_reduce)
          {
            image->depth=8;
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Reducing PNG bit depth to 8 without loss of info");
          }
      }
#endif
      /*
        Transfer most significant exception to exception argument
        FIXME: should status be used to terminate processing?
      */
      GetImageException(image,exception);
      if (image_info->number_scenes != 0)
        {
          if (mng_info->scenes_found > (long) (image_info->first_scene+image_info->number_scenes))
            break;
        }
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Finished reading image datastream.");
  } while (LocaleCompare(image_info->magick,"MNG") == 0);
  CloseBlob(image);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Finished reading all image datastreams.");
#ifdef MNG_INSERT_LAYERS
  if (insert_layers && !mng_info->image_found && (mng_info->mng_width) &&
       (mng_info->mng_height))
    {
      /*
        Insert a background layer if nothing else was found.
      */
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  No images found.  Inserting a background layer.");
      if (GetPixels(image) != (PixelPacket *) NULL)
        {
          /*
            Allocate next image structure.
          */
          AllocateNextImage(image_info,image);
          if (image->next == (Image *) NULL)
            {
              DestroyImageList(image);
              MngInfoFreeStruct(mng_info,&have_mng_structure);
              if (logging)
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "  Allocation failed, returning NULL.");
              return((Image *) NULL);
            }
          image=SyncNextImageInList(image);
        }
      image->columns=mng_info->mng_width;
      image->rows=mng_info->mng_height;
      image->page.width=mng_info->mng_width;
      image->page.height=mng_info->mng_height;
      image->page.x=0;
      image->page.y=0;
      image->background_color=mng_background_color;
      image->matte=False;
      if (!image_info->ping)
        SetImage(image,OpaqueOpacity);
      mng_info->image_found++;
    }
#endif
  image->iterations=mng_iterations;
  if (mng_iterations == 1)
    image->start_loop=True;
  while (image->previous != (Image *) NULL)
  {
    image_count++;
    if (image_count > 10*mng_info->image_found)
      {
        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  No beginning");
        (void) ThrowException2(&image->exception,(ExceptionType) CoderError,
          "Linked list is corrupted, beginning of list not found",
          image_info->filename);
        return((Image *) NULL);
      }
    image=image->previous;
    if (image->next == (Image *) NULL)
      {
        if (logging)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  Corrupt list");
      (void) ThrowException2(&image->exception,(ExceptionType) CoderError,
       "Linked list is corrupted; next_image is NULL",image_info->filename);
      }
  }
  if (mng_info->ticks_per_second && mng_info->image_found > 1 && image->next ==
     (Image *) NULL)
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  First image null");
      (void) ThrowException2(&image->exception,(ExceptionType) CoderError,
       "image->next for first image is NULL but shouldn't be.",
     image_info->filename);
    }
  if (!mng_info->image_found)
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  No visible images found.");
      (void) ThrowException2(&image->exception,(ExceptionType) CoderError,
        "No visible images in file",image_info->filename);
      if (image != (Image *) NULL)
        DestroyImageList(image);
      MngInfoFreeStruct(mng_info,&have_mng_structure);
      return((Image *) NULL);
    }

  if (mng_info->ticks_per_second)
    final_delay=100*final_delay/mng_info->ticks_per_second;
  else
    image->start_loop=True;
  /* Find final nonzero image delay */
  final_image_delay=0;
  while (image->next != (Image *) NULL)
    {
      if (image->delay)
        final_image_delay=image->delay;
      image=image->next;
    }
  if (final_delay < final_image_delay)
    final_delay=final_image_delay;
  image->delay=final_delay;
  if (logging)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  image->delay=%lu, final_delay=%lu",image->delay,final_delay);
  if (logging)
    {
      int
        scene;

      scene=0;
      while (image->previous != (Image *) NULL)
        image=image->previous;
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Before coalesce:");
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    scene 0 delay=%lu",image->delay);
      while (image->next != (Image *) NULL)
        {
          image=image->next;
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    scene %d delay=%lu",++scene,image->delay);
        }
    }

  while (image->previous != (Image *) NULL)
    image=image->previous;
#ifdef MNG_COALESCE_LAYERS
  if (insert_layers)
    {
      Image
        *next_image,
        *next;

      unsigned long
        scene;

      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  Coalesce Images");
      scene=image->scene;
      next_image=CoalesceImages(image,&image->exception);
      if (next_image == (Image *) NULL)
        MagickFatalError2(image->exception.severity,image->exception.reason,
          image->exception.description);
      DestroyImageList(image);
      image=next_image;
      for (next=image; next != (Image *) NULL; next=next_image)
      {
         next->page.width=mng_info->mng_width;
         next->page.height=mng_info->mng_height;
         next->page.x=0;
         next->page.y=0;
         next->scene=scene++;
         next_image=next->next;
         if (next_image == (Image *) NULL)
           break;
         if (next->delay == 0)
           {
             scene--;
             next_image->previous=next->previous;
             if (next->previous == (Image *) NULL)
               image=next_image;
             else
               next->previous->next=next_image;
             DestroyImage(next);
           }
      }
    }
#endif

  while (image->next != (Image *) NULL)
      image=image->next;
  image->dispose=BackgroundDispose;

  if (logging)
    {
      int
        scene;

      scene=0;
      while (image->previous != (Image *) NULL)
        image=image->previous;
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  After coalesce:");
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    scene 0 delay=%lu dispose=%d",image->delay,(int) image->dispose);
      while (image->next != (Image *) NULL)
        {
          image=image->next;
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    scene %d delay=%lu dispose=%d",++scene,
              image->delay,(int) image->dispose);
        }
    }
  while (image->previous != (Image *) NULL)
    image=image->previous;
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  have_mng_structure=False;
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit ReadMNGImage()");
  return(image);
}
#else /* PNG_LIBPNG_VER > 95 */
static Image *ReadPNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  printf("Your PNG library is too old: You have libpng-%s\n",
     PNG_LIBPNG_VER_STRING);
  (void) ThrowException2(exception,CoderError,"PNG library is too old",
    image_info->filename);
  return (Image *) NULL;
}
static Image *ReadMNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  return (ReadPNGImage(image_info,exception));
}
#endif /* PNG_LIBPNG_VER > 95 */
#endif

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r P N G I m a g e                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method RegisterPNGImage adds attributes for the PNG image format to
%  the list of supported formats.  The attributes include the image format
%  tag, a method to read and/or write the format, whether the format
%  supports the saving of more than one frame to the same file or blob,
%  whether the format supports native in-memory I/O, and a brief
%  description of the format.
%
%  The format of the RegisterPNGImage method is:
%
%      RegisterPNGImage(void)
%
*/
ModuleExport void RegisterPNGImage(void)
{
  char
    version[MaxTextExtent];

  MagickInfo
    *entry;

  static const char
    *PNGNote=
    {
      "See http://www.libpng.org/ for details about the PNG format.\n"
      "The PNG 1.2 specification is available there and at\n"
      "ftp://swrinde.nde.swri.edu/pub/png/documents/."
    },
    *JNGNote=
    {
      "See http://www.libpng.org/pub/mng/ for details about the JNG\n"
      "format. The JNG 1.0 specification is available there and at\n"
      "ftp://swrinde.nde.swri.edu/pub/mng/documents/."
    },
    *MNGNote=
    {
      "See http://www.libpng.org/pub/mng/ for details about the MNG\n"
      "format. The MNG 1.0 specification is available there and at\n"
      "ftp://swrinde.nde.swri.edu/pub/mng/documents/."
    };

  *version='\0';
#if defined(PNG_LIBPNG_VER_STRING)
  (void) strcat(version,"libpng ");
  (void) strncat(version,PNG_LIBPNG_VER_STRING,MaxTextExtent-2);
#if (PNG_LIBPNG_VER > 10005)
  if (LocaleCompare(PNG_LIBPNG_VER_STRING,png_get_header_ver(NULL)) != 0)
    {
      (void) strcat(version,",");
      (void) strncat(version,png_get_libpng_ver(NULL),MaxTextExtent-
        strlen(version)-1);
    }
#endif
#endif
  entry=SetMagickInfo("MNG");
  entry->seekable_stream=True;  /* To do: eliminate this. */
  entry->thread_support=True;
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadMNGImage;
  entry->encoder=(EncoderHandler) WriteMNGImage;
#endif
  entry->magick=(MagickHandler) IsMNG;
  entry->description=AcquireString("Multiple-image Network Graphics");
  if (*version != '\0')
    entry->version=AcquireString(version);
  entry->module=AcquireString("PNG");
  entry->note=AcquireString(MNGNote);
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG");
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadPNGImage;
  entry->encoder=(EncoderHandler) WritePNGImage;
#endif
  entry->magick=(MagickHandler) IsPNG;
  entry->adjoin=False;
  entry->thread_support=True;
  entry->description=AcquireString("Portable Network Graphics");
  entry->module=AcquireString("PNG");
  if (*version != '\0')
    entry->version=AcquireString(version);
  entry->note=AcquireString(PNGNote);
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG8");
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadPNGImage;
  entry->encoder=(EncoderHandler) WritePNGImage;
#endif
  entry->magick=(MagickHandler) IsPNG;
  entry->adjoin=False;
  entry->thread_support=True;
  entry->description=AcquireString("8-bit indexed PNG, binary transparency only");
  entry->module=AcquireString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG24");
  *version='\0';
#if defined(ZLIB_VERSION)
  (void) strcat(version,"zlib ");
  (void) strncat(version,ZLIB_VERSION,MaxTextExtent-2);
  if (LocaleCompare(ZLIB_VERSION,zlib_version) != 0)
    {
      (void) strcat(version,",");
      (void) strncat(version,zlib_version,MaxTextExtent-strlen(version)-1);
    }
#endif
  if (*version != '\0')
    entry->version=AcquireString(version);
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadPNGImage;
  entry->encoder=(EncoderHandler) WritePNGImage;
#endif
  entry->magick=(MagickHandler) IsPNG;
  entry->adjoin=False;
  entry->thread_support=True;
  entry->description=AcquireString("24-bit RGB PNG, opaque only");
  entry->module=AcquireString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("PNG32");
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadPNGImage;
  entry->encoder=(EncoderHandler) WritePNGImage;
#endif
  entry->magick=(MagickHandler) IsPNG;
  entry->adjoin=False;
  entry->thread_support=True;
  entry->description=AcquireString("32-bit RGBA PNG, semitransparency OK");
  entry->module=AcquireString("PNG");
  (void) RegisterMagickInfo(entry);

  entry=SetMagickInfo("JNG");
#if defined(JNG_SUPPORTED)
#if defined(HasPNG)
  entry->decoder=(DecoderHandler) ReadJNGImage;
  entry->encoder=(EncoderHandler) WriteJNGImage;
#endif
#endif
  entry->magick=(MagickHandler) IsJNG;
  entry->adjoin=False;
  entry->thread_support=True;
  entry->description=AcquireString("JPEG Network Graphics");
  entry->module=AcquireString("PNG");
  entry->note=AcquireString(JNGNote);
  (void) RegisterMagickInfo(entry);

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  png_semaphore=AllocateSemaphoreInfo();
#endif
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r P N G I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method UnregisterPNGImage removes format registrations made by the
%  PNG module from the list of supported formats.
%
%  The format of the UnregisterPNGImage method is:
%
%      UnregisterPNGImage(void)
%
*/
ModuleExport void UnregisterPNGImage(void)
{
  (void) UnregisterMagickInfo("MNG");
  (void) UnregisterMagickInfo("PNG");
  (void) UnregisterMagickInfo("PNG8");
  (void) UnregisterMagickInfo("PNG24");
  (void) UnregisterMagickInfo("PNG32");
  (void) UnregisterMagickInfo("JNG");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  DestroySemaphoreInfo(&png_semaphore);
#endif
}

#if defined(HasPNG)
#if PNG_LIBPNG_VER > 95
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e M N G I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method WriteMNGImage writes an image in the Portable Network Graphics
%  Group's "Multiple-image Network Graphics" encoded image format.
%
%  MNG support written by Glenn Randers-Pehrson, randeg@alum.rpi.edu
%
%  The format of the WriteMNGImage method is:
%
%      unsigned int WriteMNGImage(const ImageInfo *image_info,Image *image)
%
%  A description of each parameter follows.
%
%    o status: Method WriteMNGImage return True if the image is written.
%      False is returned is there is a memory shortage or if the image file
%      fails to write.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o image:  A pointer to an Image structure.
%
%
%  To do (as of version 5.5.2, November 26, 2002 -- glennrp -- see also
%    "To do" under ReadPNGImage):
%
%    Fix problem with palette sorting (when PNG_SORT_PALETTE is enabled,
%    some GIF animations don't convert properly)
%
%    Preserve all unknown and not-yet-handled known chunks found in input
%    PNG file and copy them  into output PNG files according to the PNG
%    copying rules.
%
%    Write the iCCP chunk at MNG level when (image->color_profile.length > 0)
%
%    Improve selection of color type (use indexed-colour or indexed-colour
%    with tRNS when 256 or fewer unique RGBA values are present).
%
%    Figure out what to do with "dispose=<restore-to-previous>" (dispose == 3)
%    This will be complicated if we limit ourselves to generating MNG-LC
%    files.  For now we ignore disposal method 3 and simply overlay the next
%    image on it.
%
%    Check for identical PLTE's or PLTE/tRNS combinations and use a
%    global MNG PLTE or PLTE/tRNS combination when appropriate.
%    [mostly done 15 June 1999 but still need to take care of tRNS]
%
%    Check for identical sRGB and replace with a global sRGB (and remove
%    gAMA/cHRM if sRGB is found; check for identical gAMA/cHRM and
%    replace with global gAMA/cHRM (or with sRGB if appropriate; replace
%    local gAMA/cHRM with local sRGB if appropriate).
%
%    Check for identical sBIT chunks and write global ones.
%
%    Provide option to skip writing the signature tEXt chunks.
%
%    Use signatures to detect identical objects and reuse the first
%    instance of such objects instead of writing duplicate objects.
%
%    Use a smaller-than-32k value of compression window size when
%    appropriate.
%
%    Encode JNG datastreams.  Mostly done as of 5.5.2; need to write
%    ancillary text chunks and save profiles.
%
%    Provide an option to force LC files (to ensure exact framing rate)
%    instead of VLC.
%
%    Provide an option to force VLC files instead of LC, even when offsets
%    are present.  This will involve expanding the embedded images with a
%    transparent region at the top and/or left.
*/


#if (PNG_LIBPNG_VER > 99 && PNG_LIBPNG_VER < 10007)
/* This function became available in libpng version 1.0.6g. */
static void
png_set_compression_buffer_size(png_structp png_ptr, png_uint_32 size)
{
    if (png_ptr->zbuf)
       png_free(png_ptr, png_ptr->zbuf); png_ptr->zbuf=NULL;
    png_ptr->zbuf_size=(png_size_t) size;
    png_ptr->zbuf=(png_bytep) png_malloc(png_ptr, size);
    if (!png_ptr->zbuf)
       png_error(png_ptr,"Unable to allocate zbuf");
}
#endif

static void
png_write_raw_profile(const ImageInfo *image_info,png_struct *ping,
   png_info *ping_info, unsigned char *profile_type, unsigned char
   *profile_description, unsigned char *profile_data, png_uint_32 length)
{
#if (PNG_LIBPNG_VER > 10005)
   png_textp
     text;

   register long
     i;

   unsigned char
     *sp;

   png_charp
     dp;

   png_uint_32
     allocated_length,
     description_length;

   unsigned char
     hex[16]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
#endif

#if (PNG_LIBPNG_VER <= 10005)
   if (image_info->verbose)
     (void) printf("Not ");
   image_info=image_info;
   ping=ping;
   ping_info=ping_info;
   profile_type=profile_type;
   profile_description=profile_description;
   profile_data=profile_data;
   length=length;
#endif
   if (image_info->verbose)
     {
     (void) printf("writing raw profile: type=%.1024s, length=%lu\n",
       profile_type, length);
     }
#if (PNG_LIBPNG_VER > 10005)
   text=(png_textp) png_malloc(ping,(png_uint_32) sizeof(png_text));
   description_length=strlen((const char *) profile_description);
   allocated_length=(png_uint_32) (length*2 + (length >> 5) + 20
      + description_length);
   text[0].text=(png_charp) png_malloc(ping,allocated_length);
   text[0].key=(png_charp) png_malloc(ping, (png_uint_32) 80);
   text[0].key[0]='\0';
   (void) strcat(text[0].key, "Raw profile type ");
   (void) strncat(text[0].key, (const char *) profile_type, 61);
   sp=profile_data;
   dp=text[0].text;
   *dp++='\n';
   (void) strcpy(dp,(const char *) profile_description);
   dp+=description_length;
   *dp++='\n';
   (void) sprintf(dp,"%8lu ",length);
   dp+=8;
   for (i=0; i < (long) length; i++)
   {
     if (i%36 == 0)
       *dp++='\n';
     *(dp++)=hex[((*sp >> 4) & 0x0f)];
     *(dp++)=hex[((*sp++ ) & 0x0f)];
   }
   *dp++='\n';
   *dp='\0';
   text[0].text_length=dp-text[0].text;
   text[0].compression=image_info->compression == NoCompression ||
     (image_info->compression == UndefinedCompression &&
     text[0].text_length < 128) ? -1 : 0;
   if (text[0].text_length <= allocated_length)
     png_set_text(ping,ping_info,text,1);
   png_free(ping,text[0].text);
   png_free(ping,text[0].key);
   png_free(ping,text);
#endif
}

static unsigned int WriteOnePNGImage(MngInfo *mng_info,
   const ImageInfo *image_info,Image *image)
{
/* Write one PNG image */
  const ImageAttribute
    *attribute;

  char
    s[2];

  int
    num_passes,
    pass;

  png_colorp
     palette;

  png_info
    *ping_info;

  png_struct
    *ping;

  long
    y;

  register IndexPacket
    *indexes;

  register long
    i,
    x;

  unsigned char
    *png_pixels;

  unsigned int
    logging,
    matte,
    not_valid;

  unsigned long
    rowbytes,
    save_image_depth;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
      "  enter WriteOnePNGImage()");

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  AcquireSemaphoreInfo(&png_semaphore);
#endif

  TransformColorspace(image,RGBColorspace);
  mng_info->IsPalette=image->storage_class == PseudoClass && image->colors <= 256;

  /*
    Allocate the PNG structures
  */
#ifdef PNG_USER_MEM_SUPPORTED
  ping=png_create_write_struct_2(PNG_LIBPNG_VER_STRING,image,
    PNGErrorHandler,PNGWarningHandler,(void *) NULL,
    (png_malloc_ptr) png_IM_malloc,(png_free_ptr) png_IM_free);
#else
  ping=png_create_write_struct(PNG_LIBPNG_VER_STRING,image,
    PNGErrorHandler,PNGWarningHandler);
#endif
  if (ping == (png_struct *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
  ping_info=png_create_info_struct(ping);
  if (ping_info == (png_info *) NULL)
    {
      png_destroy_write_struct(&ping,(png_info **) NULL);
      ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image)
    }
  png_set_write_fn(ping,image,png_put_data,png_flush_data);
  png_pixels=(unsigned char *) NULL;

  if (setjmp(ping->jmpbuf))
    {
      /*
        PNG write failed.
      */
#ifdef PNG_DEBUG
     if (image_info->verbose)
        (void) printf("PNG write has failed.\n");
#endif
      png_destroy_write_struct(&ping,&ping_info);
      MagickFreeMemory(png_pixels);
#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
      LiberateSemaphoreInfo(&png_semaphore);
#endif
      return(False);
    }
  /*
    Prepare PNG for writing.
  */
#if defined(PNG_MNG_FEATURES_SUPPORTED)
  if (mng_info->write_mng)
     png_permit_mng_features(ping,PNG_ALL_MNG_FEATURES);
#else
# ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
  if (mng_info->write_mng)
     png_permit_empty_plte(ping,True);
# endif
#endif
  x=0;
  ping_info->width=image->columns;
  ping_info->height=image->rows;
  if (logging)
    {
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    width=%lu",ping_info->width);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    height=%lu",ping_info->height);
     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    image->depth=%lu",image->depth);
    }
  if (image->depth > 16)
     image->depth=16;
  if (mng_info->write_png8 || mng_info->write_png24 || mng_info->write_png32)
     image->depth=8;
  save_image_depth=image->depth;
  ping_info->bit_depth=(png_byte) save_image_depth;
#if defined(PNG_pHYs_SUPPORTED)
  if ((image->x_resolution != 0) && (image->y_resolution != 0) &&
      (!mng_info->write_mng || !mng_info->equal_physs))
    {
      int
        unit_type;

      png_uint_32
        x_resolution,
        y_resolution;

      if (image->units == PixelsPerInchResolution)
        {
          unit_type=PNG_RESOLUTION_METER;
          x_resolution=(png_uint_32) (100.0*image->x_resolution/2.54);
          y_resolution=(png_uint_32) (100.0*image->y_resolution/2.54);
        }
      else if (image->units == PixelsPerCentimeterResolution)
        {
          unit_type=PNG_RESOLUTION_METER;
          x_resolution=(png_uint_32) (100.0*image->x_resolution);
          y_resolution=(png_uint_32) (100.0*image->y_resolution);
        }
      else
        {
          unit_type=PNG_RESOLUTION_UNKNOWN;
          x_resolution=(png_uint_32) image->x_resolution;
          y_resolution=(png_uint_32) image->y_resolution;
        }
       png_set_pHYs(ping,ping_info,x_resolution,y_resolution,unit_type);
       if (logging)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "    Setting up pHYs chunk");
    }
#endif
#if defined(PNG_oFFs_SUPPORTED)
  if (mng_info->write_mng == 0 && (image->page.x || image->page.y))
    {
       png_set_oFFs(ping,ping_info,(png_int_32) image->page.x,
          (png_int_32) image->page.y, 0);
       if (logging)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "    Setting up oFFs chunk");
    }
#endif
  if (image->matte && (!mng_info->adjoin || !mng_info->equal_backgrounds))
    {
      png_color_16
        background;

      if (image->depth < QuantumDepth)
        {
          int
             maxval;

          maxval=(1 << image->depth)-1;
          background.red=(png_uint_16)
            (maxval*image->background_color.red/MaxRGB);
          background.green=(png_uint_16)
            (maxval*image->background_color.green/MaxRGB);
          background.blue=(png_uint_16)
            (maxval*image->background_color.blue/MaxRGB);
          background.gray=(png_uint_16)
            (maxval*PixelIntensity(&image->background_color)/MaxRGB);
        }
      else
        {
          background.red=image->background_color.red;
          background.green=image->background_color.green;
          background.blue=image->background_color.blue;
          background.gray=
            (png_uint_16) PixelIntensity(&image->background_color);
        }
      background.index=(png_byte) background.gray;
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Setting up bKGd chunk");
      png_set_bKGD(ping,ping_info,&background);
    }
  /*
    Select the color type.
  */
  matte=image->matte;
  if (mng_info->write_png8)
    {
      ping_info->color_type=PNG_COLOR_TYPE_PALETTE;
      ping_info->bit_depth=8;
        {
          /* TO DO: make this a function cause it's used twice, except
             for reducing the sample depth from 8. */

          QuantizeInfo
            quantize_info;

          unsigned long
             number_colors,
             save_number_colors;

          number_colors=image->colors;
          if (number_colors == 0 || number_colors > 256)
            {
              GetQuantizeInfo(&quantize_info);
              quantize_info.dither=image_info->dither;
              quantize_info.number_colors=256;
              (void) QuantizeImage(&quantize_info,image);
              number_colors=image->colors;
              SyncImage(image);
              if (logging)
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                    "    Colors quantized to %ld",number_colors);
            }
          if (matte)
             ping_info->valid|=PNG_INFO_tRNS;
          /*
            Set image palette.
          */
          ping_info->color_type=PNG_COLOR_TYPE_PALETTE;
          ping_info->valid|=PNG_INFO_PLTE;
#if defined(PNG_SORT_PALETTE)
          save_number_colors=image->colors;
          (void) CompressColormapTransFirst(image);
          number_colors=image->colors;
          image->colors=save_number_colors;
#endif
          palette=MagickAllocateMemory(png_color *,
            number_colors*sizeof(png_color));
          if (palette == (png_color *) NULL)
            ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Setting up PLTE chunk");
          for (i=0; i < (long) number_colors; i++)
          {
            palette[i].red=ScaleQuantumToChar(image->colormap[i].red);
            palette[i].green=ScaleQuantumToChar(image->colormap[i].green);
            palette[i].blue=ScaleQuantumToChar(image->colormap[i].blue);
            if (logging)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
#if QuantumDepth == 8
                  "    %3ld (%3d,%3d,%3d)",
#else
                  "    %5ld (%5d,%5d,%5d)",
#endif
                  i,palette[i].red,palette[i].green,palette[i].blue);

          }
          png_set_PLTE(ping,ping_info,palette,(int) number_colors);
#if (PNG_LIBPNG_VER > 10008)
          MagickFreeMemory(palette);
#endif
          /*
            Identify which colormap entry is transparent.
          */
          ping_info->trans=MagickAllocateMemory(unsigned char *,number_colors);
          if (ping_info->trans == (unsigned char *) NULL)
            ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
          assert(number_colors <= 256);
          for (i=0; i < (long) number_colors; i++)
             ping_info->trans[i]=255;
          for (y=0; y < (long) image->rows; y++)
          {
            register const PixelPacket
              *p=NULL;

            p=AcquireImagePixels(image,0,y,image->columns,1,
                &image->exception);
            if (p == (const PixelPacket *) NULL)
              break;
            indexes=GetIndexes(image);
            for (x=0; x < (long) image->columns; x++)
            {
              if (p->opacity != OpaqueOpacity)
                {
                  IndexPacket
                    index;

                  index=indexes[x];
                  assert((unsigned long) index < number_colors);
                  ping_info->trans[index]=(png_byte) (255-
                    ScaleQuantumToChar(p->opacity));
                }
              p++;
            }
          }
          ping_info->num_trans=0;
          for (i=0; i < (long) number_colors; i++)
            if (ping_info->trans[i] != 255)
              ping_info->num_trans=(unsigned short) (i+1);
          if (ping_info->num_trans == 0)
            ping_info->valid&=(~PNG_INFO_tRNS);
          if (!(ping_info->valid & PNG_INFO_tRNS))
            ping_info->num_trans=0;
          if (ping_info->num_trans == 0)
            MagickFreeMemory(ping_info->trans);
          /*
            Identify which colormap entry is the background color.
          */
          for (i=0; i < (long) Max(number_colors-1,1); i++)
            if (RGBColorMatchExact(ping_info->background,image->colormap[i]))
              break;
          ping_info->background.index=(png_uint_16) i;
        }
      if (image->matte)
        {
          /* TO DO: reduce to binary transparency */
        }
    }
  else if (mng_info->write_png24)
    {
      image->matte=False;
      ping_info->color_type=PNG_COLOR_TYPE_RGB;
    }
  else if (mng_info->write_png32)
    {
      image->matte=True;
      ping_info->color_type=PNG_COLOR_TYPE_RGB_ALPHA;
    }
  else
    {
      if (ping_info->bit_depth < 8)
        ping_info->bit_depth=8;
      if (mng_info->optimize || mng_info->IsPalette || image_info->type ==
          BilevelType)
        {
          if (ImageIsMonochrome(image))
            {
              if (!image->matte)
                ping_info->bit_depth=1;
            }
        }
      ping_info->color_type=PNG_COLOR_TYPE_RGB;
      if (image_info->type == GrayscaleType)
        ping_info->color_type=PNG_COLOR_TYPE_GRAY;
      if (image_info->type == GrayscaleMatteType)
        ping_info->color_type=PNG_COLOR_TYPE_GRAY_ALPHA;
      if (!mng_info->optimize && matte)
        ping_info->color_type=PNG_COLOR_TYPE_RGB_ALPHA;

      if (logging)
        {
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Tentative PNG color type: %d",ping_info->color_type);
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    image_info->type: %d",image_info->type);
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    image->depth: %lu",image->depth);
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    ping_info->bit_depth: %d",ping_info->bit_depth);
        }

      if (matte && (mng_info->optimize || mng_info->IsPalette))
        {
          register const PixelPacket
            *p=NULL;

          ping_info->color_type=PNG_COLOR_TYPE_GRAY_ALPHA;
          for (y=0; y < (long) image->rows; y++)
          {
            p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
            if (p == (const PixelPacket *) NULL)
              break;
            for (x=(long) image->columns; x > 0; x--)
            {
              if (!IsGray(*p))
                {
                  ping_info->color_type=PNG_COLOR_TYPE_RGB_ALPHA;
                  break;
                }
              p++;
            }
          }
          /*
            Determine if there is any transparent color.
          */
          for (y=0; y < (long) image->rows; y++)
          {
            p=AcquireImagePixels(image,0,y,image->columns,1,&image->exception);
            if (p == (const PixelPacket *) NULL)
              break;
            for (x=(long) image->columns; x > 0; x--)
            {
              if (p->opacity != OpaqueOpacity)
                break;
              p++;
            }
            if (x != 0)
              break;
          }
          if ((y == (long) image->rows) && (x == (long) image->columns))
            {
              /*
                No transparent pixels are present.  Change 4 or 6 to 0 or 2,
                and do not set the PNG_INFO_tRNS flag in ping_info->valid.
              */
              image->matte=False;
              ping_info->color_type&=0x03;
            }
          else
            {
              unsigned int
                mask;

              mask=0xffff;
              if (ping_info->bit_depth == 8)
                 mask=0x00ff;
              if (ping_info->bit_depth == 4)
                 mask=0x000f;
              if (ping_info->bit_depth == 2)
                 mask=0x0003;
              if (ping_info->bit_depth == 1)
                 mask=0x0001;
              ping_info->valid|=PNG_INFO_tRNS;
              ping_info->trans_values.red=ScaleQuantumToShort(p->red)&mask;
              ping_info->trans_values.green=ScaleQuantumToShort(p->green)&mask;
              ping_info->trans_values.blue=ScaleQuantumToShort(p->blue)&mask;
              ping_info->trans_values.gray=
                 (png_uint_16) ScaleQuantumToShort(PixelIntensity(p))&mask;
              ping_info->trans_values.index=(unsigned char)
                 (ScaleQuantumToChar(MaxRGB-p->opacity));
            }
          if (ping_info->valid & PNG_INFO_tRNS)
            {
              /*
                Determine if there is one and only one transparent color
                and if so if it is fully transparent.
              */
              for (y=0; y < (long) image->rows; y++)
              {
                p=AcquireImagePixels(image,0,y,image->columns,1,
                   &image->exception);
                x=0;
                if (p == (const PixelPacket *) NULL)
                  break;
                for (x=(long) image->columns; x > 0; x--)
                {
                  if (p->opacity != OpaqueOpacity)
                    {
                      if (!RGBColorMatchExact(ping_info->trans_values,*p))
                      {
                         break;  /* Can't use RGB + tRNS for multiple
                                    transparent colors.  */
                      }
                      if (p->opacity != TransparentOpacity)
                      {
                         break;  /* Can't use RGB + tRNS for
                                    semitransparency. */
                      }
                    }
                   else
                    {
                      if (RGBColorMatchExact(ping_info->trans_values,*p))
                          break; /* Can't use RGB + tRNS when another pixel
                                    having the same RGB samples is
                                    transparent. */
                    }
                p++;
                }
                if (x != 0)
                   break;
              }
              if (x != 0)
                ping_info->valid&=(~PNG_INFO_tRNS);
            }
          if (ping_info->valid & PNG_INFO_tRNS)
            {
              ping_info->color_type &= 0x03;  /* changes 4 or 6 to 0 or 2 */
              if (image->depth == 8)
                {
                  ping_info->trans_values.red&=0xff;
                  ping_info->trans_values.green&=0xff;
                  ping_info->trans_values.blue&=0xff;
                  ping_info->trans_values.gray&=0xff;
                }
            }
        }
    matte=image->matte;
    if (ping_info->valid & PNG_INFO_tRNS)
      image->matte=False;
    if ((mng_info->optimize || mng_info->IsPalette) &&
        ImageIsGray(image) && (!image->matte || image->depth >= 8))
      {
        if (image->matte)
            ping_info->color_type=PNG_COLOR_TYPE_GRAY_ALPHA;
        else
          {
            ping_info->color_type=PNG_COLOR_TYPE_GRAY;
            if (save_image_depth == 16 && image->depth == 8)
              ping_info->trans_values.gray*=0x0101;
          }
        if (image->depth > QuantumDepth)
          image->depth=QuantumDepth;
        if (image->colors == 0 || image->colors-1 > MaxRGB)
          image->colors=1 << image->depth;
        if (image->depth > 8)
          ping_info->bit_depth=16;
        else
          {
            if (ping_info->color_type == PNG_COLOR_TYPE_PALETTE)
              {
                ping_info->bit_depth=1;
                while ((int) (1 << ping_info->bit_depth) < (long) image->colors)
                  ping_info->bit_depth <<= 1;
              }
            else if (mng_info->optimize && ping_info->color_type ==
                PNG_COLOR_TYPE_GRAY && image->colors < 17 && mng_info->IsPalette)
              {

              /* Check if grayscale is reducible */
                int
                  i,
                  depth_4_ok=True,
                  depth_2_ok=True,
                  depth_1_ok=True;

                for (i=0; i < (long) image->colors; i++)
                {
                   unsigned char
                     intensity;

                   intensity=ScaleQuantumToChar(image->colormap[i].red);

                   if ((intensity & 0x0f) != ((intensity & 0xf0) >> 4))
                     depth_4_ok=depth_2_ok=depth_1_ok=False;
                   else if ((intensity & 0x03) != ((intensity & 0x0c) >> 2))
                     depth_2_ok=depth_1_ok=False;
                   else if ((intensity & 0x01) != ((intensity & 0x02) >> 1))
                     depth_1_ok=False;
                }
                if (depth_1_ok)
                   ping_info->bit_depth=1;
                else if (depth_2_ok)
                   ping_info->bit_depth=2;
                else if (depth_4_ok)
                   ping_info->bit_depth=4;
              }
          }
      }
    else
      if (mng_info->IsPalette)
      {
        if (image->depth <= 8)
          {
            unsigned long
               number_colors;

            number_colors=image->colors;
            if (matte)
               ping_info->valid|=PNG_INFO_tRNS;
            /*
              Set image palette.
            */
            ping_info->color_type=PNG_COLOR_TYPE_PALETTE;
            ping_info->valid|=PNG_INFO_PLTE;
            if (mng_info->have_write_global_plte && !matte)
              {
                 png_set_PLTE(ping,ping_info,NULL,0);
                 if (logging)
                   (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                       "  Setting up empty PLTE chunk");
              }
            else
              {
#if defined(PNG_SORT_PALETTE)
                unsigned long
                   save_number_colors;

                if (mng_info->optimize)
                  {
                    save_number_colors=image->colors;
                    (void) CompressColormapTransFirst(image);
                    number_colors=image->colors;
                    image->colors=save_number_colors;
                  }
#endif
                palette=MagickAllocateMemory(png_color *,
                  number_colors*sizeof(png_color));
                if (palette == (png_color *) NULL)
                  ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
                for (i=0; i < (long) number_colors; i++)
                {
                  palette[i].red=ScaleQuantumToChar(image->colormap[i].red);
                  palette[i].green=ScaleQuantumToChar(image->colormap[i].green);
                  palette[i].blue=ScaleQuantumToChar(image->colormap[i].blue);
                }
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "  Setting up PLTE chunk");
                png_set_PLTE(ping,ping_info,palette,(int) number_colors);
#if (PNG_LIBPNG_VER > 10008)
                MagickFreeMemory(palette);
#endif
              }
            ping_info->bit_depth=1;
            while ((1UL << ping_info->bit_depth) < number_colors)
              ping_info->bit_depth <<= 1;
            ping_info->num_trans=0;
            if (matte)
            {
              /*
                Identify which colormap entry is transparent.
              */
              ping_info->trans=MagickAllocateMemory(unsigned char *,
                  number_colors);
              if (ping_info->trans == (unsigned char *) NULL)
                ThrowWriterException(ResourceLimitError,
                    MemoryAllocationFailed,image);
              assert(number_colors <= 256);
              for (i=0; i < (long) number_colors; i++)
                 ping_info->trans[i]=255;
              for (y=0; y < (long) image->rows; y++)
              {
                register const PixelPacket
                  *p=NULL;

                p=AcquireImagePixels(image,0,y,image->columns,1,
                    &image->exception);
                if (p == (const PixelPacket *) NULL)
                  break;
                indexes=GetIndexes(image);
                for (x=0; x < (long) image->columns; x++)
                {
                  if (p->opacity != OpaqueOpacity)
                    {
                      IndexPacket
                        index;

                      index=indexes[x];
                      assert((unsigned long) index < number_colors);
                      ping_info->trans[index]=(png_byte) (255-
                        ScaleQuantumToChar(p->opacity));
                    }
                  p++;
                }
              }
              for (i=0; i < (long) number_colors; i++)
                if (ping_info->trans[i] != 255)
                  ping_info->num_trans=(unsigned short) (i+1);
              if (ping_info->num_trans == 0)
                ping_info->valid&=(~PNG_INFO_tRNS);
              if (!(ping_info->valid & PNG_INFO_tRNS))
                ping_info->num_trans=0;
              if (ping_info->num_trans == 0)
                MagickFreeMemory(ping_info->trans);
            }

            /*
              Identify which colormap entry is the background color.
            */
            for (i=0; i < (long) Max(number_colors-1,1); i++)
              if (RGBColorMatchExact(ping_info->background,image->colormap[i]))
                break;
            ping_info->background.index=(png_uint_16) i;
          }
      }
    else
      {
        if (image->depth < 8)
          image->depth=8;
        if ((save_image_depth == 16) && (image->depth == 8))
          {
            ping_info->trans_values.red*=0x0101;
            ping_info->trans_values.green*=0x0101;
            ping_info->trans_values.blue*=0x0101;
            ping_info->trans_values.gray*=0x0101;
          }
      }

    /*
      Adjust background and transparency samples in sub-8-bit grayscale files.
    */
    if (ping_info->bit_depth < 8 && ping_info->color_type ==
        PNG_COLOR_TYPE_GRAY)
      {
         png_uint_16
           maxval;

         png_color_16
           background;

         maxval=(1 << ping_info->bit_depth)-1;


         background.gray=(png_uint_16)
           (maxval*(PixelIntensity(&image->background_color))/MaxRGB);

         if (logging)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "  Setting up bKGD chunk");
         png_set_bKGD(ping,ping_info,&background);

         ping_info->trans_values.gray=(png_uint_16)(maxval*
           ping_info->trans_values.gray/MaxRGB);
      }
    }
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    PNG color type: %d",ping_info->color_type);
  /*
    Initialize compression level and filtering.
  */
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Setting up deflate compression");
#if (PNG_LIBPNG_VER > 99)
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Compression buffer size: 32768");
  png_set_compression_buffer_size(ping,32768L);
#endif
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "    Compression mem level: 9");
  png_set_compression_mem_level(ping, 9);
  if (image_info->quality > 9)
    {
      int
        level;

      level=(int) Min(image_info->quality/10,9);
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Compression level: %d",level);
      png_set_compression_level(ping,level);
    }
  else
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Compression strategy: Z_HUFFMAN_ONLY");
      png_set_compression_strategy(ping, Z_HUFFMAN_ONLY);
    }
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Setting up filtering");
#if defined(PNG_MNG_FEATURES_SUPPORTED) && defined(PNG_INTRAPIXEL_DIFFERENCING)

  /* This became available in libpng-1.0.9.  Output must be a MNG. */
  if (mng_info->write_mng && ((image_info->quality % 10) == 7))
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Filter_type: PNG_INTRAPIXEL_DIFFERENCING");
      ping_info->filter_type=PNG_INTRAPIXEL_DIFFERENCING;
    }
  else
    if (logging)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Filter_type: 0");
#endif
  {
    int
      base_filter;

    if ((image_info->quality % 10) > 5)
        base_filter=PNG_ALL_FILTERS;
    else
      if ((image_info->quality % 10) != 5)
        base_filter=(int) image_info->quality % 10;
      else
        if ((ping_info->color_type == PNG_COLOR_TYPE_GRAY) ||
            (ping_info->color_type == PNG_COLOR_TYPE_PALETTE) ||
            (image_info->quality < 50))
          base_filter=PNG_NO_FILTERS;
        else
            base_filter=PNG_ALL_FILTERS;
    if (logging)
      {
        if (base_filter == PNG_ALL_FILTERS)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Base filter method: ADAPTIVE");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "    Base filter method: NONE");
      }
    png_set_filter(ping,PNG_FILTER_TYPE_BASE,base_filter);
  }

  if (image->color_profile.length)
#if (PNG_LIBPNG_VER > 10008) && defined(PNG_WRITE_iCCP_SUPPORTED)
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up iCCP chunk");
      if (image->color_profile.name == (png_charp) NULL ||
          *image->color_profile.name == '\0')
        png_set_iCCP(ping,ping_info,(png_charp) "icm",
           (int) 0, (png_charp) image->color_profile.info,
           (png_uint_32) image->color_profile.length);
      else
        png_set_iCCP(ping,ping_info,(png_charp) image->color_profile.name,
           (int) 0, (png_charp) image->color_profile.info,
           (png_uint_32) image->color_profile.length);
    }
#else
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk with iCCP Profile");
      png_write_raw_profile(image_info,ping,ping_info,
          (unsigned char *) "icm",
          (unsigned char *) "ICC Profile",
          (unsigned char *) image->color_profile.info,
          (png_uint_32) image->color_profile.length);
    }
#endif
  if (image->iptc_profile.length != 0)
    {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk with iPTC Profile");
      png_write_raw_profile(image_info,ping,ping_info,
        (unsigned char *) "iptc",
        (unsigned char *) "IPTC profile",
        (unsigned char *) image->iptc_profile.info,
        (png_uint_32) image->iptc_profile.length);
    }
  for (i=0; i < (long) image->generic_profiles; i++)
  {
    if (image->generic_profile[i].name == (png_charp) NULL)
      {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk with generic profile");
        png_write_raw_profile(image_info,ping,ping_info,
          (unsigned char *) "generic",
          (unsigned char *) "generic profile",
          (unsigned char *) image->generic_profile[i].info,
          (png_uint_32) image->generic_profile[i].length);
      }
    else
      {
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk with %s profile",
            image->generic_profile[i].name);
        png_write_raw_profile(image_info,ping,ping_info,
          (unsigned char *) image->generic_profile[i].name,
          (unsigned char *) "generic profile",
          (unsigned char *) image->generic_profile[i].info,
          (png_uint_32) image->generic_profile[i].length);
      }
  }

#if defined(PNG_WRITE_sRGB_SUPPORTED)
  if (!mng_info->have_write_global_srgb &&
      ((image->rendering_intent != UndefinedIntent) ||
      image_info->colorspace == sRGBColorspace))
    {
      /*
        Note image rendering intent.
      */
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up sRGB chunk");
      if (image->rendering_intent != UndefinedIntent)
        (void) png_set_sRGB(ping,ping_info,(int) (image->rendering_intent-1));
      else
        (void) png_set_sRGB(ping,ping_info,PerceptualIntent);
      png_set_gAMA(ping,ping_info,0.45455);
    }
  not_valid=(!ping_info->valid);
  if ((!mng_info->write_mng) || not_valid & PNG_INFO_sRGB)
#endif
    {
      if (!mng_info->have_write_global_gama && (image->gamma != 0.0))
        {
          /*
            Note image gamma.
            To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
          */
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Setting up gAMA chunk");
          png_set_gAMA(ping,ping_info,image->gamma);
        }
      if (!mng_info->have_write_global_chrm &&
          (image->chromaticity.red_primary.x != 0.0))
        {
          /*
            Note image chromaticity.
            To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
          */
           PrimaryInfo
             bp,
             gp,
             rp,
             wp;

           wp=image->chromaticity.white_point;
           rp=image->chromaticity.red_primary;
           gp=image->chromaticity.green_primary;
           bp=image->chromaticity.blue_primary;

           if (logging)
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "  Setting up cHRM chunk");
           png_set_cHRM(ping,ping_info,wp.x,wp.y,rp.x,rp.y,gp.x,gp.y,
               bp.x,bp.y);
       }
    }
  ping_info->interlace_type=image_info->interlace != NoInterlace;

  if (mng_info->write_mng)
    png_set_sig_bytes(ping,8);

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Writing PNG header chunks");

  png_write_info(ping,ping_info);

  png_set_packing(ping);
  /*
    Allocate memory.
  */
  rowbytes=image->columns;
  if (image->depth == 8)
    {
      if (mng_info->write_png24)
        rowbytes*=3;
      else if (mng_info->write_png32)
        rowbytes*=4;
      else if (!mng_info->write_png8 &&
          ((mng_info->optimize || mng_info->IsPalette) && ImageIsGray(image)))
        rowbytes*=(image->matte ? 2 : 1);
      else
        {
          if (!mng_info->IsPalette)
            rowbytes*=(image->matte ? 4 : 3);
        }
    }
  else
    if (image->depth == 16)
      {
        if ((mng_info->optimize || mng_info->IsPalette) &&
            ImageIsGray(image))
          rowbytes*=(image->matte ? 4 : 2);
        else
          rowbytes*=(image->matte ? 8 : 6);
      }
  png_pixels=MagickAllocateMemory(unsigned char *,rowbytes);
  if (png_pixels == (unsigned char *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize image scanlines.
  */
  num_passes=png_set_interlace_handling(ping);
  if ((!mng_info->write_png8 && !mng_info->write_png24 && !mng_info->write_png32) &&
      (mng_info->optimize || mng_info->IsPalette || image_info->type == BilevelType) &&
      !image->matte && ImageIsMonochrome(image))
    for (pass=0; pass < num_passes; pass++)
    {
      /*
        Convert PseudoClass image to a PNG monochrome image.
      */
      for (y=0; y < (long) image->rows; y++)
      {
        if (!AcquireImagePixels(image,0,y,image->columns,1,&image->exception))
          break;
        if (mng_info->IsPalette)
              (void) PopImagePixels(image,(QuantumType) GrayQuantum,
                png_pixels);
        else
          (void) PopImagePixels(image,(QuantumType) RedQuantum,png_pixels);
        for (i=0; i < (long) image->columns; i++)
           *(png_pixels+i)=(*(png_pixels+i) > 128) ? 255 : 0;
        png_write_row(ping,png_pixels);
      }
      if (image->previous == (Image *) NULL)
        if (!MagickMonitor(SaveImageTag,pass,num_passes,&image->exception))
          break;
    }
  else
    for (pass=0; pass < num_passes; pass++)
    {
      if ((!mng_info->write_png8 && !mng_info->write_png24 && !mng_info->write_png32) &&
         (!image->matte || (ping_info->bit_depth >= QuantumDepth)) &&
         (mng_info->optimize || mng_info->IsPalette) && ImageIsGray(image))
      {
        for (y=0; y < (long) image->rows; y++)
        {
          if (!AcquireImagePixels(image,0,y,image->columns,1,
              &image->exception))
            break;
          if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
            {
              if (mng_info->IsPalette)
                (void) PopImagePixels(image,(QuantumType) GrayQuantum,
                   png_pixels);
              else
                (void) PopImagePixels(image,(QuantumType) RedQuantum,
                   png_pixels);
            }
          else /* PNG_COLOR_TYPE_GRAY_ALPHA */
            {
              (void) PopImagePixels(image,(QuantumType) GrayAlphaQuantum,
                 png_pixels);
            }
          png_write_row(ping,png_pixels);
        }
        if (image->previous == (Image *) NULL)
          if (!MagickMonitor(SaveImageTag,pass,num_passes,&image->exception))
            break;
      }
    else
      for (pass=0; pass < num_passes; pass++)
      {
        if ((image->depth > 8) || (mng_info->write_png24 || mng_info->write_png32 ||
            (!mng_info->write_png8 && !mng_info->IsPalette)))
          for (y=0; y < (long) image->rows; y++)
          {
            if (!AcquireImagePixels(image,0,y,image->columns,1,
                &image->exception))
              break;
            if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
              {
                if (image->storage_class == DirectClass)
                  (void) PopImagePixels(image,(QuantumType) RedQuantum,
                     png_pixels);
                else
                  (void) PopImagePixels(image,(QuantumType) GrayQuantum,
                    png_pixels);
              }
            else if (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
              (void) PopImagePixels(image,(QuantumType) GrayAlphaQuantum,
                 png_pixels);
            else if (image->matte)
              (void) PopImagePixels(image,(QuantumType) RGBAQuantum,
                png_pixels);
            else
              (void) PopImagePixels(image,(QuantumType) RGBQuantum,
                png_pixels);
            png_write_row(ping,png_pixels);
          }
      else
        for (y=0; y < (long) image->rows; y++)
        {
          if (!AcquireImagePixels(image,0,y,image->columns,1,
                &image->exception))
            break;
          if (ping_info->color_type == PNG_COLOR_TYPE_GRAY)
            (void) PopImagePixels(image,(QuantumType) GrayQuantum,
              png_pixels);
          else if (ping_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
            (void) PopImagePixels(image,(QuantumType) GrayAlphaQuantum,
              png_pixels);
          else
            (void) PopImagePixels(image,(QuantumType) IndexQuantum,
              png_pixels);
          png_write_row(ping,png_pixels);
        }
        if (image->previous == (Image *) NULL)
          if (!MagickMonitor(SaveImageTag,pass,num_passes,&image->exception))
            break;
     }
  }

  if (logging)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Writing PNG image data");
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Width: %lu",ping_info->width);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Height: %lu",ping_info->height);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG sample depth: %d",ping_info->bit_depth);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG color type: %d",ping_info->color_type);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    PNG Interlace method: %d",
          ping_info->interlace_type);
    }
  /*
    Generate text chunks.
  */
#if (PNG_LIBPNG_VER <= 10005)
  ping_info->num_text=0;
#endif
  attribute=GetImageAttribute(image,(char *) NULL);
  for ( ; attribute != (const ImageAttribute *) NULL;
      attribute=attribute->next)
  {
#if (PNG_LIBPNG_VER > 10005)
    png_textp
      text;
#endif

    if (*attribute->key == '[')
      continue;
#if (PNG_LIBPNG_VER > 10005)
    text=(png_textp) png_malloc(ping,(png_uint_32) sizeof(png_text));
    text[0].key=attribute->key;
    text[0].text=attribute->value;
    text[0].text_length=strlen(attribute->value);
    text[0].compression=image_info->compression == NoCompression ||
      (image_info->compression == UndefinedCompression &&
      text[0].text_length < 128) ? -1 : 0;
    if (logging)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk");
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    keyword: %s",text[0].key);
      }
    png_set_text(ping,ping_info,text,1);
    png_free(ping,text);
#else
/* Work directly with ping_info struct; png_set_text before libpng version
 * 1.0.5a is leaky */
    if (ping_info->num_text == 0)
      {
        ping_info->text=MagickAllocateMemory(png_text *,256*sizeof(png_text));
        if (ping_info->text == (png_text *) NULL)
          (void) ThrowException(&image->exception,(ExceptionType) ResourceLimitError,MemoryAllocationFailed,image->filename);
      }
    i=ping_info->num_text++;
    if (i > 255)
      (void) ThrowException(&image->exception,(ExceptionType) ResourceLimitError,
        "Cannot write more than 256 PNG text chunks",image->filename);
    ping_info->text[i].key=attribute->key;
    ping_info->text[i].text=attribute->value;
    ping_info->text[i].text_length=strlen(attribute->value);
    ping_info->text[i].compression=image_info->compression == NoCompression ||
      (image_info->compression == UndefinedCompression &&
      ping_info->text[i].text_length < 128) ? -1 : 0;
    if (logging)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Setting up text chunk");
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    keyword: %s",ping_info->text[i].key);
      }
#endif
  }
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Writing PNG end info");
  png_write_end(ping,ping_info);
  if (mng_info->need_fram && (int) image->dispose == BackgroundDispose)
    {
      if (mng_info->page.x || mng_info->page.y || (ping_info->width != mng_info->page.width) ||
          (ping_info->height != mng_info->page.height))
        {
          unsigned char
            chunk[32];

          /*
            Write FRAM 4 with clipping boundaries followed by FRAM 1.
          */
          (void) WriteBlobMSBULong(image,27L);  /* data length=27 */
          PNGType(chunk,mng_FRAM);
          LogPNGChunk(logging,mng_FRAM,27L);
          chunk[4]=4;
          chunk[5]=0;  /* frame name separator (no name) */
          chunk[6]=1;  /* flag for changing delay, for next frame only */
          chunk[7]=0;  /* flag for changing frame timeout */
          chunk[8]=1;  /* flag for changing frame clipping for next frame */
          chunk[9]=0;  /* flag for changing frame sync_id */
          PNGLong(chunk+10,(png_uint_32) (0L)); /* temporary 0 delay */
          chunk[14]=0; /* clipping boundaries delta type */
          PNGLong(chunk+15,(png_uint_32) (mng_info->page.x)); /* left cb */
          PNGLong(chunk+19,(png_uint_32) (mng_info->page.x + ping_info->width));
          PNGLong(chunk+23,(png_uint_32) (mng_info->page.y)); /* top cb */
          PNGLong(chunk+27,(png_uint_32) (mng_info->page.y + ping_info->height));
          (void) WriteBlob(image,31,(char *) chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,31));
          mng_info->old_framing_mode=4;
          mng_info->framing_mode=1;
        }
      else
        mng_info->framing_mode=3;
    }
  if (mng_info->write_mng && !mng_info->need_fram &&
      ((int) image->dispose == 3))
     (void) ThrowException2(&image->exception,(ExceptionType) CoderError,
       "Cannot convert GIF with disposal method 3 to MNG-LC",(char *) NULL);
  image->depth=save_image_depth;

  /* Save depth actually written */

  s[0]=(char) ping_info->bit_depth;
  s[1]='\0';

  (void) SetImageAttribute(image,"[png_bit_depth]",s);

  /*
    Free PNG resources.
  */
#if (PNG_LIBPNG_VER < 10007)
  if (ping_info->valid & PNG_INFO_PLTE)
    {
      MagickFreeMemory(ping_info->palette);
      ping_info->valid&=(~PNG_INFO_PLTE);
    }
#endif
  if (ping_info->valid & PNG_INFO_tRNS)
    {
      MagickFreeMemory(ping_info->trans);
      ping_info->valid&=(~PNG_INFO_tRNS);
    }
  png_destroy_write_struct(&ping,&ping_info);

  MagickFreeMemory(png_pixels);

#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
  LiberateSemaphoreInfo(&png_semaphore);
#endif

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  exit WriteOnePNGImage()");
  return (True);
/*  End write one PNG image */
}

static unsigned int WritePNGImage(const ImageInfo *image_info,Image *image)
{
  MngInfo
    *mng_info;

  int
    have_mng_structure;

  unsigned int
    logging,
    status;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter WritePNGImage()");
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == False)
    ThrowWriterException(FileOpenError,UnableToOpenFile,image);

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=False;
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=True;
  mng_info->write_png8=LocaleCompare(image_info->magick,"PNG8") == 0;
  mng_info->write_png24=LocaleCompare(image_info->magick,"PNG24") == 0;
  mng_info->write_png32=LocaleCompare(image_info->magick,"PNG32") == 0;

  status=WriteOnePNGImage(mng_info,image_info,image);

  CloseBlob(image);

  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WritePNGImage()");
  return (status);
}

#if defined(JNG_SUPPORTED)

/* Write one JNG image */
static unsigned int WriteOneJNGImage(MngInfo *mng_info,
   const ImageInfo *image_info,Image *image)
{
  Image
    *jpeg_image;

  ImageInfo
    *jpeg_image_info;

  char
    *blob;

  size_t
    length;

  unsigned char
    chunk[80],
    *p;

  unsigned int
    jng_alpha_compression_method,
    jng_alpha_sample_depth,
    jng_color_type,
    logging,
    status,
    transparent;

  unsigned long
    jng_quality;

  logging=LogMagickEvent(CoderEvent,GetMagickModule(),
      "  enter WriteOneJNGImage()");

  blob=(char *) NULL;
  jpeg_image=(Image *) NULL;
  jpeg_image_info=(ImageInfo *) NULL;

  status=True;
  transparent=image_info->type==GrayscaleMatteType ||
     image_info->type==TrueColorMatteType;
  jng_color_type=10;
  jng_alpha_sample_depth=0;
  jng_quality=image_info->quality;
  jng_alpha_compression_method=0;

  if (image->matte)
    {
      /* if any pixels are transparent */
      transparent=True;
      if (image_info->compression==JPEGCompression)
        jng_alpha_compression_method=8;
    }

  if (transparent)
    {
      jng_color_type=14;
      /* Create JPEG blob, image, and image_info */
      if (logging)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Creating jpeg_image_info for opacity.");
      jpeg_image_info=(ImageInfo *) CloneImageInfo(image_info);
      if (jpeg_image_info == (ImageInfo *) NULL)
        ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,
            image);
      if (logging)
        LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Creating jpeg_image.");
      jpeg_image=CloneImage(image,0,0,True,&image->exception);
      if (jpeg_image == (Image *) NULL)
        ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,
            image);
      DestroyBlob(jpeg_image);
      jpeg_image->blob=CloneBlobInfo((BlobInfo *) NULL);
      status=ChannelImage(jpeg_image,OpacityChannel);
      status=NegateImage(jpeg_image,False);
      jpeg_image->matte=False;
      if (jng_quality >= 1000)
        jpeg_image_info->quality=jng_quality/1000;
      else
        jpeg_image_info->quality=jng_quality;
      jpeg_image_info->type=GrayscaleType;
      SetImageType(jpeg_image,GrayscaleType);
      AcquireUniqueFilename(jpeg_image->filename);
      FormatString(jpeg_image_info->filename,"%.1024s",
          jpeg_image->filename);
    }

  /* To do: check bit depth of PNG alpha channel */

  /* Check if image is grayscale. */
  if (image_info->type != TrueColorMatteType && image_info->type !=
    TrueColorType && ImageIsGray(image))
    jng_color_type-=2;

  if (transparent)
    {
      if (jng_alpha_compression_method==0)
        {
          const ImageAttribute
            *attribute;

          /* Encode opacity as a grayscale PNG blob */
          status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
            &image->exception);
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Creating PNG blob.");
          length=0;

          (void) strncpy(jpeg_image_info->magick,"PNG",MaxTextExtent-1);
          (void) strncpy(jpeg_image->magick,"PNG",MaxTextExtent-1);
          jpeg_image_info->interlace=NoInterlace;

          blob=(char *) ImageToBlob(jpeg_image_info,jpeg_image,&length,
              &image->exception);

          /* Retrieve sample depth used */
          attribute=GetImageAttribute(jpeg_image,"[png_bit_depth]");
          if ((attribute != (const ImageAttribute *) NULL) &&
              (attribute->value != (char *) NULL))
          jng_alpha_sample_depth= (unsigned int) attribute->value[0];
        }
      else
        {
          /* Encode opacity as a grayscale JPEG blob */

          status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
            &image->exception);

          (void) strncpy(jpeg_image_info->magick,"JPEG",MaxTextExtent-1);
          (void) strncpy(jpeg_image->magick,"JPEG",MaxTextExtent-1);
          jpeg_image_info->interlace=NoInterlace;
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Creating blob.");
          blob=(char *) ImageToBlob(jpeg_image_info,jpeg_image,&length,
              &image->exception);
          jng_alpha_sample_depth=8;
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Successfully read jpeg_image into a blob, length=%lu.",
                 (unsigned long) length);

        }
      /* Destroy JPEG image and image_info */
      LiberateUniqueFileResource(jpeg_image_info->filename);
      DestroyImage(jpeg_image);
      DestroyImageInfo(jpeg_image_info);
    }

  /* Write JHDR chunk */
  (void) WriteBlobMSBULong(image,16L);  /* chunk data length=16 */
  PNGType(chunk,mng_JHDR);
  LogPNGChunk(logging,mng_JHDR,16L);
  PNGLong(chunk+4,image->columns);
  PNGLong(chunk+8,image->rows);
  chunk[12]=jng_color_type;
  chunk[13]=8;  /* sample depth */
  chunk[14]=8; /*jng_image_compression_method */
  chunk[15]=image_info->interlace == NoInterlace ? 0 : 8;
  chunk[16]=jng_alpha_sample_depth;
  chunk[17]=jng_alpha_compression_method;
  chunk[18]=0; /*jng_alpha_filter_method */
  chunk[19]=0; /*jng_alpha_interlace_method */
  (void) WriteBlob(image,20,(char *) chunk);
  (void) WriteBlobMSBULong(image,crc32(0,chunk,20));
  if (logging)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG width:%15lu",image->columns);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG height:%14lu",image->rows);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG color type:%10d",jng_color_type);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG sample depth:%8d",8);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG compression:%9d",8);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG interlace:%11d",0);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG alpha depth:%9d",jng_alpha_sample_depth);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG alpha compression:%3d",jng_alpha_compression_method);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG alpha filter:%8d",0);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    JNG alpha interlace:%5d",0);
    }

  /*
     Write leading ancillary chunks
  */

  if (transparent)
  {
    /*
      Write JNG bKGD chunk
    */

    char
      blue,
      green,
      red;

    long
      num_bytes;

    if (jng_color_type == 8 || jng_color_type == 12)
      num_bytes=6L;
    else
      num_bytes=10L;
    (void) WriteBlobMSBULong(image,num_bytes-4L);
    PNGType(chunk,mng_bKGD);
    LogPNGChunk(logging,mng_bKGD,num_bytes-4L);
    red=ScaleQuantumToChar(image->background_color.red);
    green=ScaleQuantumToChar(image->background_color.green);
    blue=ScaleQuantumToChar(image->background_color.blue);
    *(chunk+4)=0;
    *(chunk+5)=red;
    *(chunk+6)=0;
    *(chunk+7)=green;
    *(chunk+8)=0;
    *(chunk+9)=blue;
    (void) WriteBlob(image,num_bytes,(char *) chunk);
    (void) WriteBlobMSBULong(image,crc32(0,chunk,num_bytes));
  }

  if ((image_info->colorspace == sRGBColorspace || image->rendering_intent))
    {
      /*
        Write JNG sRGB chunk
      */
      (void) WriteBlobMSBULong(image,1L);
      PNGType(chunk,mng_sRGB);
      LogPNGChunk(logging,mng_sRGB,1L);
      if (image->rendering_intent != UndefinedIntent)
        chunk[4]=(int) image->rendering_intent-1;
      else
        chunk[4]=(int) PerceptualIntent-1;
      (void) WriteBlob(image,5,(char *) chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
    }
  else
    {
      if (image->gamma)
        {
          /*
             Write JNG gAMA chunk
          */
          (void) WriteBlobMSBULong(image,4L);
          PNGType(chunk,mng_gAMA);
          LogPNGChunk(logging,mng_gAMA,4L);
          PNGLong(chunk+4,(unsigned long) (100000*image->gamma+0.5));
          (void) WriteBlob(image,8,(char *) chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,8));
        }
      if (!mng_info->equal_chrms && image->chromaticity.red_primary.x != 0.0)
        {
          PrimaryInfo
            primary;

          /*
             Write JNG cHRM chunk
          */
          (void) WriteBlobMSBULong(image,32L);
          PNGType(chunk,mng_cHRM);
          LogPNGChunk(logging,mng_cHRM,32L);
          primary=image->chromaticity.white_point;
          PNGLong(chunk+4,(unsigned long) (100000*primary.x+0.5));
          PNGLong(chunk+8,(unsigned long) (100000*primary.y+0.5));
          primary=image->chromaticity.red_primary;
          PNGLong(chunk+12,(unsigned long) (100000*primary.x+0.5));
          PNGLong(chunk+16,(unsigned long) (100000*primary.y+0.5));
          primary=image->chromaticity.green_primary;
          PNGLong(chunk+20,(unsigned long) (100000*primary.x+0.5));
          PNGLong(chunk+24,(unsigned long) (100000*primary.y+0.5));
          primary=image->chromaticity.blue_primary;
          PNGLong(chunk+28,(unsigned long) (100000*primary.x+0.5));
          PNGLong(chunk+32,(unsigned long) (100000*primary.y+0.5));
          (void) WriteBlob(image,36,(char *) chunk);
          (void) WriteBlobMSBULong(image,crc32(0,chunk,36));
        }
    }
  if (image->x_resolution && image->y_resolution && !mng_info->equal_physs)
    {
      /*
         Write JNG pHYs chunk
      */
      (void) WriteBlobMSBULong(image,9L);
      PNGType(chunk,mng_pHYs);
      LogPNGChunk(logging,mng_pHYs,9L);
      if (image->units == PixelsPerInchResolution)
        {
          PNGLong(chunk+4,(unsigned long)
            (image->x_resolution*100.0/2.54+0.5));
          PNGLong(chunk+8,(unsigned long)
            (image->y_resolution*100.0/2.54+0.5));
          chunk[12]=1;
        }
      else
        {
          if (image->units == PixelsPerCentimeterResolution)
            {
              PNGLong(chunk+4,(unsigned long)
                (image->x_resolution*100.0+0.5));
              PNGLong(chunk+8,(unsigned long)
                (image->y_resolution*100.0+0.5));
              chunk[12]=1;
            }
          else
            {
              PNGLong(chunk+4,(unsigned long) (image->x_resolution+0.5));
              PNGLong(chunk+8,(unsigned long) (image->y_resolution+0.5));
              chunk[12]=0;
            }
        }
      (void) WriteBlob(image,13,(char *) chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
    }

  if (mng_info->write_mng == 0 && (image->page.x || image->page.y))
    {
      /*
         Write JNG oFFs chunk
      */
      (void) WriteBlobMSBULong(image,9L);
      PNGType(chunk,mng_oFFs);
      LogPNGChunk(logging,mng_oFFs,9L);
      PNGsLong(chunk+4,(long) (image->page.x));
      PNGsLong(chunk+8,(long) (image->page.y));
      chunk[12]=0;
      (void) WriteBlob(image,13,(char *) chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
    }

  if (transparent)
    {
      if (jng_alpha_compression_method==0)
        {
          long
            len;

          register long
            i;

          /* Write IDAT chunk header */
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Write IDAT chunks from blob, length=%lu.",
                (unsigned long) length);

          /* Copy IDAT chunks */
          len=0;
          p=(unsigned char *) (blob+8);
          for (i=8; i<(long) length; i+=len+12)
          {
            len=(*p<<24)|((*(p+1))<<16)|((*(p+2))<<8)|(*(p+3));
            p+=4;
            if (*(p)==73 && *(p+1)==68 && *(p+2)==65 && *(p+3)==84) /* IDAT */
              {
                /* Found an IDAT chunk. */
                (void) WriteBlobMSBULong(image,(unsigned long) len);
                LogPNGChunk(logging,mng_IDAT,len);
                (void) WriteBlob(image,len+4,(char *) p);
                (void) WriteBlobMSBULong(image,
                    crc32(0,p,len+4));
              }
            else
              {
                if (logging)
                  (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                      "    Skipping %c%c%c%c chunk, length=%lu.",
                      *(p),*(p+1),*(p+2),*(p+3),len);
              }
            p+=(8+len);
          }
        }
      else
        {
          /* Write JDAA chunk header */
          if (logging)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "  Write JDAA chunk, length=%lu.",
                (unsigned long) length);
          (void) WriteBlobMSBULong(image,(unsigned long) length);
          PNGType(chunk,mng_JDAA);
          LogPNGChunk(logging,mng_JDAA,length);
          /* Write JDAT chunk(s) data */
          (void) WriteBlob(image,4,(char *) chunk);
          (void) WriteBlob(image,length,(char *) blob);
          (void) WriteBlobMSBULong(image,crc32(crc32(0,chunk,4),
              (unsigned char *) blob,length));
        }
      MagickFreeMemory(blob);
    }

  /* Encode image as a JPEG blob */
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Creating jpeg_image_info.");
  jpeg_image_info=(ImageInfo *) CloneImageInfo(image_info);
  if (jpeg_image_info == (ImageInfo *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,
        image);

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Creating jpeg_image.");

  jpeg_image=CloneImage(image,0,0,True,&image->exception);
  if (jpeg_image == (Image *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,
        image);
  DestroyBlob(jpeg_image);
  jpeg_image->blob=CloneBlobInfo((BlobInfo *) NULL);
  AcquireUniqueFilename(jpeg_image->filename);
  FormatString(jpeg_image_info->filename,"%.1024s",jpeg_image->filename);

  status=OpenBlob(jpeg_image_info,jpeg_image,WriteBinaryBlobMode,
    &image->exception);

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Created jpeg_image, %lu x %lu.",jpeg_image->columns,
        jpeg_image->rows);

  if (jng_color_type == 8 || jng_color_type == 12)
    jpeg_image_info->type=GrayscaleType;
  jpeg_image_info->quality=jng_quality%1000;
  (void) strncpy(jpeg_image_info->magick,"JPEG",MaxTextExtent-1);
  (void) strncpy(jpeg_image->magick,"JPEG",MaxTextExtent-1);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Creating blob.");
  blob=(char *) ImageToBlob(jpeg_image_info,jpeg_image,&length,
      &image->exception);
  if (logging)
    {
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Successfully read jpeg_image into a blob, length=%lu.",
          (unsigned long) length);

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "  Write JDAT chunk, length=%lu.",
         (unsigned long) length);
    }
  /* Write JDAT chunk(s) */
  (void) WriteBlobMSBULong(image,(unsigned long) length);
  PNGType(chunk,mng_JDAT);
  LogPNGChunk(logging,mng_JDAT,length);
  (void) WriteBlob(image,4,(char *) chunk);
  (void) WriteBlob(image,length,(char *) blob);
  (void) WriteBlobMSBULong(image,crc32(crc32(0,chunk,4),(unsigned char *)
      blob,length));

  LiberateUniqueFileResource(jpeg_image_info->filename);
  DestroyImage(jpeg_image);
  DestroyImageInfo(jpeg_image_info);
  MagickFreeMemory(blob);

  /* Write IEND chunk */
  (void) WriteBlobMSBULong(image,0L);
  PNGType(chunk,mng_IEND);
  LogPNGChunk(logging,mng_IEND,0);
  (void) WriteBlob(image,4,(char *) chunk);
  (void) WriteBlobMSBULong(image,crc32(0,chunk,4));

  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  exit WriteOneJNGImage()");
  return(status);
}


static unsigned int WriteJNGImage(const ImageInfo *image_info,Image *image)
{
  MngInfo
    *mng_info;

  int
    have_mng_structure;

  unsigned int
    logging,
    status;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter WriteJNGImage()");
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == False)
    ThrowWriterException(FileOpenError,UnableToOpenFile,image);

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=False;
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=True;

  (void) WriteBlob(image,8,"\213JNG\r\n\032\n");

  status=WriteOneJNGImage(mng_info,image_info,image);
  CloseBlob(image);

  CatchImageException(image);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WriteJNGImage()");
  return (status);
}
#endif



static unsigned int WriteMNGImage(const ImageInfo *image_info,Image *image)
{
  Image
    *next_image;

  MngInfo
    *mng_info;

  int
    have_mng_structure,
    image_count,
    need_iterations,
    need_matte;

  volatile int
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    need_local_plte,
#endif
    all_images_are_gray,
    logging,
    need_defi,
    optimize,
    use_global_plte;

  register long
    i;

  unsigned char
    chunk[800];

  unsigned int
    status;

  volatile unsigned int
    scene,
    write_jng,
    write_mng;

  unsigned long
    final_delay=0,
    initial_delay;

#if (PNG_LIBPNG_VER < 10007)
    if (image_info->verbose)
      printf("Your PNG library (libpng-%s) is rather old.\n",
         PNG_LIBPNG_VER_STRING);
#endif

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  logging=LogMagickEvent(CoderEvent,GetMagickModule(),"enter WriteMNGImage()");
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == False)
    ThrowWriterException(FileOpenError,UnableToOpenFile,image);

  /*
    Allocate a MngInfo structure.
  */
  have_mng_structure=False;
  mng_info=MagickAllocateMemory(MngInfo *,sizeof(MngInfo));
  if (mng_info == (MngInfo *) NULL)
    ThrowWriterException(ResourceLimitError,MemoryAllocationFailed,image);
  /*
    Initialize members of the MngInfo structure.
  */
  (void) memset(mng_info,0,sizeof(MngInfo));
  mng_info->image=image;
  have_mng_structure=True;

  write_mng=LocaleCompare(image_info->magick,"MNG") == 0;
  mng_info->write_png8=LocaleCompare(image_info->magick,"PNG8") == 0;
  mng_info->write_png24=LocaleCompare(image_info->magick,"PNG24") == 0;
  mng_info->write_png32=LocaleCompare(image_info->magick,"PNG32") == 0;

  write_jng=False;
  if (image_info->compression==JPEGCompression)
    write_jng=True;
  else
  {
    Image
      *p;

    for (p=image; p != (Image *) NULL; p=p->next)
    {
      if (p->compression==JPEGCompression)
        write_jng=True;
    }
  }

  mng_info->adjoin=image_info->adjoin && (image->next != (Image *) NULL) &&
    write_mng;

  if (mng_info->write_png8 || mng_info->write_png24 || mng_info->write_png32)
    optimize=False;
  else
    optimize=(image_info->type == OptimizeType || image_info->type ==
      UndefinedType);

  if (logging)
    {
      /* Log some info about the input */
      Image
        *p;

      long
        scene;

      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "  Checking input image(s)");
      if (optimize)
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Optimize: TRUE");
      else
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Optimize: FALSE");
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Image_info depth: %ld",
          image_info->depth);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "    Type: %d",image_info->type);

      scene=0;
      for (p=image; p != (Image *) NULL; p=p->next)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "    Scene: %ld",scene++);
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "      Image depth: %lu",p->depth);
        if (p->matte)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Matte: True");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Matte: False");
        if (p->storage_class == PseudoClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Storage class: PseudoClass");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Storage class: DirectClass");
        if (p->colors)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Number of colors: %lu",p->colors);
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "      Number of colors: unspecified");
        if (!mng_info->adjoin)
          break;
      }
    }

  /*
    Sometimes we get PseudoClass images whose RGB values don't match
    the colors in the colormap.  This code syncs the RGB values.
  */
  {
    Image
      *p;

    for (p=image; p != (Image *) NULL; p=p->next)
    {
      if (p->taint && p->storage_class == PseudoClass)
         SyncImage(p);
      if (!mng_info->adjoin)
        break;
    }
  }

#ifdef PNG_BUILD_PALETTE
  if (optimize)
    {
      /*
        Sometimes we get DirectClass images that have 256 colors or fewer.
        This code will convert them to PseudoClass and build a colormap.
      */
      Image
        *p;

      for (p=image; p != (Image *) NULL; p=p->next)
      {
        if (p->storage_class != PseudoClass)
          {
            p->colors=GetNumberColors(p,(FILE *) NULL,&p->exception);
            if (p->colors <= 256)
              {
                p->colors=0;
                if (p->matte)
                    SetImageType(p,PaletteMatteType);
                else
                    SetImageType(p,PaletteType);
              }
          }
        if (!mng_info->adjoin)
          break;
      }
    }
#endif

  use_global_plte=False;
  all_images_are_gray=False;
#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
  need_local_plte=True;
#endif
  need_defi=False;
  need_matte=False;
  mng_info->framing_mode=1;
  mng_info->old_framing_mode=1;

  if (write_mng)
      if (image_info->page != (char *) NULL)
        {
          /*
            Determine image bounding box.
          */
          SetGeometry(image,&mng_info->page);
          (void) ParseMetaGeometry(image_info->page,&mng_info->page.x,
            &mng_info->page.y,&mng_info->page.width,&mng_info->page.height);
        }
  if (write_mng)
    {
      unsigned int
        need_geom;

      unsigned short
        red,
        green,
        blue;

      mng_info->page=image->page;
      need_geom=True;
      if (mng_info->page.width || mng_info->page.height)
         need_geom=False;
      /*
        Check all the scenes.
      */
      initial_delay=(long) image->delay;
      need_iterations=False;
      mng_info->equal_chrms=image->chromaticity.red_primary.x != 0.0;
      mng_info->equal_physs=True,
      mng_info->equal_gammas=True;
      mng_info->equal_srgbs=True;
      mng_info->equal_backgrounds=True;
      image_count=0;
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
      all_images_are_gray=True;
      mng_info->equal_palettes=False;
      need_local_plte=False;
#endif
      for (next_image=image; next_image != (Image *) NULL; )
      {
        if (need_geom)
          {
            if ((next_image->columns+next_image->page.x) > mng_info->page.width)
              mng_info->page.width=next_image->columns+next_image->page.x;
            if ((next_image->rows+next_image->page.y) > mng_info->page.height)
              mng_info->page.height=next_image->rows+next_image->page.y;
          }
        if (next_image->page.x || next_image->page.y)
          need_defi=True;
        if (next_image->matte)
          need_matte=True;
        if ((int) next_image->dispose >= BackgroundDispose)
          if (next_image->matte || next_image->page.x || next_image->page.y ||
              ((next_image->columns < mng_info->page.width) &&
               (next_image->rows < mng_info->page.height)))
            mng_info->need_fram=True;
        if (next_image->iterations)
          need_iterations=True;
        final_delay=next_image->delay;
        if (final_delay != initial_delay || final_delay > 100)
          mng_info->need_fram=1;
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
        /*
          check for global palette possibility.
        */
        if (image->matte)
           need_local_plte=True;
        if (!need_local_plte)
          {
            if (!ImageIsGray(image))
              all_images_are_gray=False;
            mng_info->equal_palettes=PalettesAreEqual(image,next_image);
            if (!use_global_plte)
              use_global_plte=mng_info->equal_palettes;
            need_local_plte=!mng_info->equal_palettes;
          }
#endif
        if (next_image->next != (Image *) NULL)
          {
            if (next_image->background_color.red !=
                next_image->next->background_color.red ||
                next_image->background_color.green !=
                next_image->next->background_color.green ||
                next_image->background_color.blue !=
                next_image->next->background_color.blue)
              mng_info->equal_backgrounds=False;
            if (next_image->gamma != next_image->next->gamma)
              mng_info->equal_gammas=False;
            if (next_image->rendering_intent !=
                next_image->next->rendering_intent)
              mng_info->equal_srgbs=False;
            if ((next_image->units != next_image->next->units) ||
                (next_image->x_resolution != next_image->next->x_resolution) ||
                (next_image->y_resolution != next_image->next->y_resolution))
              mng_info->equal_physs=False;
            if (mng_info->equal_chrms)
              {
                if (next_image->chromaticity.red_primary.x !=
                    next_image->next->chromaticity.red_primary.x ||
                    next_image->chromaticity.red_primary.y !=
                    next_image->next->chromaticity.red_primary.y ||
                    next_image->chromaticity.green_primary.x !=
                    next_image->next->chromaticity.green_primary.x ||
                    next_image->chromaticity.green_primary.y !=
                    next_image->next->chromaticity.green_primary.y ||
                    next_image->chromaticity.blue_primary.x !=
                    next_image->next->chromaticity.blue_primary.x ||
                    next_image->chromaticity.blue_primary.y !=
                    next_image->next->chromaticity.blue_primary.y ||
                    next_image->chromaticity.white_point.x !=
                    next_image->next->chromaticity.white_point.x ||
                    next_image->chromaticity.white_point.y !=
                    next_image->next->chromaticity.white_point.y)
                  mng_info->equal_chrms=False;
              }
          }
        image_count++;
        next_image=next_image->next;
      }
      if (image_count < 2)
        {
          mng_info->equal_backgrounds=False;
          mng_info->equal_chrms=False;
          mng_info->equal_gammas=False;
          mng_info->equal_srgbs=False;
          mng_info->equal_physs=False;
          use_global_plte=False;
#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
          need_local_plte=True;
#endif
          need_iterations=False;
        }
     if (!mng_info->need_fram)
       {
         /*
           Only certain framing rates 100/n are exactly representable without
           the FRAM chunk but we'll allow some slop in VLC files
         */
         if (final_delay == 0)
           {
             if (need_iterations)
               {
                 /*
                   It's probably a GIF with loop; don't run it *too* fast.
                 */
                 final_delay=10;
                 (void) ThrowException2(&image->exception,CoderError,
                   "input has zero delay between all frames; assuming 10 cs",
                   (char *) NULL);
               }
             else
               mng_info->ticks_per_second=0;
           }
         if (final_delay)
           mng_info->ticks_per_second=100/final_delay;
         if (final_delay > 50)
           mng_info->ticks_per_second=2;
         if (final_delay > 75)
           mng_info->ticks_per_second=1;
         if (final_delay > 125)
           mng_info->need_fram=True;
         if (need_defi && final_delay > 2 && (final_delay != 4) &&
            (final_delay != 5) && (final_delay != 10) && (final_delay != 20) &&
            (final_delay != 25) && (final_delay != 50) && (final_delay != 100))
           mng_info->need_fram=True;  /* make it exact; cannot be VLC anyway */
       }
     if (mng_info->need_fram)
        mng_info->ticks_per_second=100;
     /*
        If pseudocolor, we should also check to see if all the
        palettes are identical and write a global PLTE if they are.
        ../glennrp Feb 99.
     */
     /*
        Write the MNG version 1.0 signature and MHDR chunk.
     */
     (void) WriteBlob(image,8,"\212MNG\r\n\032\n");
     (void) WriteBlobMSBULong(image,28L);  /* chunk data length=28 */
     PNGType(chunk,mng_MHDR);
     LogPNGChunk(logging,mng_MHDR,28L);
     PNGLong(chunk+4,mng_info->page.width);
     PNGLong(chunk+8,mng_info->page.height);
     PNGLong(chunk+12,mng_info->ticks_per_second);
     PNGLong(chunk+16,0L);  /* layer count=unknown */
     PNGLong(chunk+20,0L);  /* frame count=unknown */
     PNGLong(chunk+24,0L);  /* play time=unknown   */
     if (write_jng)
       {
         if (need_matte)
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,27L);    /* simplicity=LC+JNG */
             else
               PNGLong(chunk+28,25L);    /* simplicity=VLC+JNG */
           }
         else
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,19L);    /* simplicity=LC+JNG, no transparency */
             else
               PNGLong(chunk+28,17L);    /* simplicity=VLC+JNG, no transparency */
           }
       }
     else
       {
         if (need_matte)
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,11L);    /* simplicity=LC */
             else
               PNGLong(chunk+28,9L);    /* simplicity=VLC */
           }
         else
           {
             if (need_defi || mng_info->need_fram || use_global_plte)
               PNGLong(chunk+28,3L);    /* simplicity=LC, no transparency */
             else
               PNGLong(chunk+28,1L);    /* simplicity=VLC, no transparency */
           }
       }
     (void) WriteBlob(image,32,(char *) chunk);
     (void) WriteBlobMSBULong(image,crc32(0,chunk,32));
     if ((image->previous == (Image *) NULL) &&
         (image->next != (Image *) NULL) && (image->iterations != 1))
       {
         /*
           Write MNG TERM chunk
         */
         (void) WriteBlobMSBULong(image,10L);  /* data length=10 */
         PNGType(chunk,mng_TERM);
         LogPNGChunk(logging,mng_TERM,10L);
         chunk[4]=3;  /* repeat animation */
         chunk[5]=0;  /* show last frame when done */
         PNGLong(chunk+6,(png_uint_32) (mng_info->ticks_per_second*final_delay/100));
         if (image->iterations == 0)
           PNGLong(chunk+10,PNG_MAX_UINT);
         else
           PNGLong(chunk+10,(png_uint_32) image->iterations);
         if (logging)
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                 "     TERM delay: %lu",
                 (png_uint_32) (mng_info->ticks_per_second*final_delay/100));
             if (image->iterations == 0)
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "     TERM iterations: %lu",PNG_MAX_UINT);
             else
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                   "     Image iterations: %lu",image->iterations);
           }
         (void) WriteBlob(image,14,(char *) chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,14));
       }
     /*
       To do: check for cHRM+gAMA == sRGB, and write sRGB instead.
     */
     if ((image_info->colorspace == sRGBColorspace || image->rendering_intent) &&
          mng_info->equal_srgbs)
       {
         /*
           Write MNG sRGB chunk
         */
         (void) WriteBlobMSBULong(image,1L);
         PNGType(chunk,mng_sRGB);
         LogPNGChunk(logging,mng_sRGB,1L);
         if (image->rendering_intent != UndefinedIntent)
           chunk[4]=(int) image->rendering_intent-1;
         else
           chunk[4]=(int) PerceptualIntent-1;
         (void) WriteBlob(image,5,(char *) chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
         mng_info->have_write_global_srgb=True;
       }
     else
       {
         if (image->gamma && mng_info->equal_gammas)
           {
             /*
                Write MNG gAMA chunk
             */
             (void) WriteBlobMSBULong(image,4L);
             PNGType(chunk,mng_gAMA);
             LogPNGChunk(logging,mng_gAMA,4L);
             PNGLong(chunk+4,(unsigned long) (100000*image->gamma+0.5));
             (void) WriteBlob(image,8,(char *) chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,8));
             mng_info->have_write_global_gama=True;
           }
         if (mng_info->equal_chrms)
           {
             PrimaryInfo
               primary;

             /*
                Write MNG cHRM chunk
             */
             (void) WriteBlobMSBULong(image,32L);
             PNGType(chunk,mng_cHRM);
             LogPNGChunk(logging,mng_cHRM,32L);
             primary=image->chromaticity.white_point;
             PNGLong(chunk+4,(unsigned long) (100000*primary.x+0.5));
             PNGLong(chunk+8,(unsigned long) (100000*primary.y+0.5));
             primary=image->chromaticity.red_primary;
             PNGLong(chunk+12,(unsigned long) (100000*primary.x+0.5));
             PNGLong(chunk+16,(unsigned long) (100000*primary.y+0.5));
             primary=image->chromaticity.green_primary;
             PNGLong(chunk+20,(unsigned long) (100000*primary.x+0.5));
             PNGLong(chunk+24,(unsigned long) (100000*primary.y+0.5));
             primary=image->chromaticity.blue_primary;
             PNGLong(chunk+28,(unsigned long) (100000*primary.x+0.5));
             PNGLong(chunk+32,(unsigned long) (100000*primary.y+0.5));
             (void) WriteBlob(image,36,(char *) chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,36));
             mng_info->have_write_global_chrm=True;
           }
       }
     if (image->x_resolution && image->y_resolution && mng_info->equal_physs)
       {
         /*
            Write MNG pHYs chunk
         */
         (void) WriteBlobMSBULong(image,9L);
         PNGType(chunk,mng_pHYs);
         LogPNGChunk(logging,mng_pHYs,9L);
         if (image->units == PixelsPerInchResolution)
           {
             PNGLong(chunk+4,(unsigned long)
               (image->x_resolution*100.0/2.54+0.5));
             PNGLong(chunk+8,(unsigned long)
               (image->y_resolution*100.0/2.54+0.5));
             chunk[12]=1;
           }
         else
           {
             if (image->units == PixelsPerCentimeterResolution)
               {
                 PNGLong(chunk+4,(unsigned long)
                   (image->x_resolution*100.0+0.5));
                 PNGLong(chunk+8,(unsigned long)
                   (image->y_resolution*100.0+0.5));
                 chunk[12]=1;
               }
             else
               {
                 PNGLong(chunk+4,(unsigned long) (image->x_resolution+0.5));
                 PNGLong(chunk+8,(unsigned long) (image->y_resolution+0.5));
                 chunk[12]=0;
               }
           }
         (void) WriteBlob(image,13,(char *) chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,13));
       }
     /*
       Write MNG BACK chunk and global bKGD chunk, if the image is transparent
       or does not cover the entire frame.
     */
     if (write_mng && (image->matte || image->page.x > 0 || image->page.y > 0 ||
         (image->page.width && (image->page.width+image->page.x < mng_info->page.width))
         || (image->page.height && (image->page.height+image->page.y
         < mng_info->page.height))))
       {
         (void) WriteBlobMSBULong(image,6L);
         PNGType(chunk,mng_BACK);
         LogPNGChunk(logging,mng_BACK,6L);
         red=ScaleQuantumToShort(image->background_color.red);
         green=ScaleQuantumToShort(image->background_color.green);
         blue=ScaleQuantumToShort(image->background_color.blue);
         PNGShort(chunk+4,red);
         PNGShort(chunk+6,green);
         PNGShort(chunk+8,blue);
         (void) WriteBlob(image,10,(char *) chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,10));
         if (mng_info->equal_backgrounds)
           {
             (void) WriteBlobMSBULong(image,6L);
             PNGType(chunk,mng_bKGD);
             LogPNGChunk(logging,mng_bKGD,6L);
             (void) WriteBlob(image,10,(char *) chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,10));
           }
       }

#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
     if (!need_local_plte && image->storage_class == PseudoClass
         && !all_images_are_gray)
       {
         unsigned long
           data_length;

         /*
           Write MNG PLTE chunk
         */
         data_length=3*image->colors;
         (void) WriteBlobMSBULong(image,data_length);
         PNGType(chunk,mng_PLTE);
         LogPNGChunk(logging,mng_PLTE,data_length);
         for (i=0; i < (long) image->colors; i++)
         {
           chunk[4+i*3]=ScaleQuantumToChar(image->colormap[i].red) & 0xff;
           chunk[5+i*3]=ScaleQuantumToChar(image->colormap[i].green) & 0xff;
           chunk[6+i*3]=ScaleQuantumToChar(image->colormap[i].blue) & 0xff;
         }
         (void) WriteBlob(image,data_length+4,(char *) chunk);
         (void) WriteBlobMSBULong(image,crc32(0,chunk,(int) (data_length+4)));
         mng_info->have_write_global_plte=True;
       }
#endif
    }
  scene=0;
  mng_info->delay=0;
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
  mng_info->equal_palettes=False;
#endif
  do
  {
    if (mng_info->adjoin)
    {
#if defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED) || \
    defined(PNG_MNG_FEATURES_SUPPORTED)
    /*
      If we aren't using a global palette for the entire MNG, check to
      see if we can use one for two or more consecutive images.
    */
    if (need_local_plte && use_global_plte && !all_images_are_gray)
      {
        if (mng_info->IsPalette)
          {
            /*
              When equal_palettes is true, this image has the same palette
              as the previous PseudoClass image
            */
            mng_info->have_write_global_plte=mng_info->equal_palettes;
            mng_info->equal_palettes=PalettesAreEqual(image,image->next);
            if (mng_info->equal_palettes && !mng_info->have_write_global_plte)
              {
                /*
                  Write MNG PLTE chunk
                */
                unsigned long
                  data_length;

                data_length=3*image->colors;
                (void) WriteBlobMSBULong(image,data_length);
                PNGType(chunk,mng_PLTE);
                LogPNGChunk(logging,mng_PLTE,data_length);
                for (i=0; i < (long) image->colors; i++)
                {
                  chunk[4+i*3]=ScaleQuantumToChar(image->colormap[i].red);
                  chunk[5+i*3]=ScaleQuantumToChar(image->colormap[i].green);
                  chunk[6+i*3]=ScaleQuantumToChar(image->colormap[i].blue);
                }
                (void) WriteBlob(image,data_length+4,(char *) chunk);
                (void) WriteBlobMSBULong(image,crc32(0,chunk,
                   (int) (data_length+4)));
                mng_info->have_write_global_plte=True;
              }
          }
        else
          mng_info->have_write_global_plte=False;
      }
#endif
    if (need_defi)
      {
        long
          previous_x,
          previous_y;

        if (scene)
          {
            previous_x=mng_info->page.x;
            previous_y=mng_info->page.y;
          }
        else
          {
            previous_x=0;
            previous_y=0;
          }
        mng_info->page=image->page;
        if ((mng_info->page.x !=  previous_x) || (mng_info->page.y != previous_y))
          {
             (void) WriteBlobMSBULong(image,12L);  /* data length=12 */
             PNGType(chunk,mng_DEFI);
             LogPNGChunk(logging,mng_DEFI,12L);
             chunk[4]=0; /* object 0 MSB */
             chunk[5]=0; /* object 0 LSB */
             chunk[6]=0; /* visible  */
             chunk[7]=0; /* abstract */
             PNGLong(chunk+8,mng_info->page.x);
             PNGLong(chunk+12,mng_info->page.y);
             (void) WriteBlob(image,16,(char *) chunk);
             (void) WriteBlobMSBULong(image,crc32(0,chunk,16));
          }
      }
    }

   mng_info->write_mng=write_mng;

   if ((int) image->dispose >= 3)
     mng_info->framing_mode=3;

   if (mng_info->need_fram && mng_info->adjoin && ((image->delay !=
      mng_info->delay) || (mng_info->framing_mode !=
      mng_info->old_framing_mode)))
     {
       unsigned char
         chunk[16];

       if (image->delay == mng_info->delay)
         {
           /*
             Write a MNG FRAM chunk with the new framing mode.
           */
           (void) WriteBlobMSBULong(image,1L);  /* data length=1 */
           PNGType(chunk,mng_FRAM);
           LogPNGChunk(logging,mng_FRAM,1L);
           chunk[4]=(unsigned char) mng_info->framing_mode;
           (void) WriteBlob(image,5,(char *) chunk);
           (void) WriteBlobMSBULong(image,crc32(0,chunk,5));
         }
       else
         {
           /*
             Write a MNG FRAM chunk with the delay.
           */
           (void) WriteBlobMSBULong(image,10L);  /* data length=10 */
           PNGType(chunk,mng_FRAM);
           LogPNGChunk(logging,mng_FRAM,10L);
           chunk[4]=(unsigned char) mng_info->framing_mode;
           chunk[5]=0;  /* frame name separator (no name) */
           chunk[6]=2;  /* flag for changing default delay */
           chunk[7]=0;  /* flag for changing frame timeout */
           chunk[8]=0;  /* flag for changing frame clipping */
           chunk[9]=0;  /* flag for changing frame sync_id */
           PNGLong(chunk+10,(png_uint_32)
             ((mng_info->ticks_per_second*image->delay)/100));
           (void) WriteBlob(image,14,(char *) chunk);
           (void) WriteBlobMSBULong(image,crc32(0,chunk,14));
           mng_info->delay=(long) image->delay;
         }
       mng_info->old_framing_mode=mng_info->framing_mode;
     }

#if defined(JNG_SUPPORTED)
   if (image->compression == JPEGCompression)
     {
       if (logging)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Writing JNG object.");
       /* To do: specify the desired alpha compression method. */
       image->compression=UndefinedCompression;
       status=WriteOneJNGImage(mng_info,image_info,image);
     }
   else
#endif
     {
       if (logging)
         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
             "  Writing PNG object.");
       status=WriteOnePNGImage(mng_info,image_info,image);
     }

    if (!status)
      {
        MngInfoFreeStruct(mng_info,&have_mng_structure);
        CloseBlob(image);
        return (False);
      }
    CatchImageException(image);
    if (image->next == (Image *) NULL)
      break;
    image=SyncNextImageInList(image);
    if (!MagickMonitor(SaveImagesTag,scene++,GetImageListLength(image),
        &image->exception))
      break;
  } while (mng_info->adjoin);
  if (write_mng)
    {
      while (image->previous != (Image *) NULL)
        image=image->previous;
      /*
        Write the MEND chunk.
      */
      (void) WriteBlobMSBULong(image,0x00000000L);
      PNGType(chunk,mng_MEND);
      LogPNGChunk(logging,mng_MEND,0L);
      (void) WriteBlob(image,4,(char *) chunk);
      (void) WriteBlobMSBULong(image,crc32(0,chunk,4));
    }
  /*
    Free memory.
  */
  CloseBlob(image);
  MngInfoFreeStruct(mng_info,&have_mng_structure);
  if (logging)
    (void) LogMagickEvent(CoderEvent,GetMagickModule(),"exit WriteMNGImage()");
  return(True);
}
#else /* PNG_LIBPNG_VER > 95 */
static unsigned int WritePNGImage(const ImageInfo *image_info,Image *image)
{
  image=image;
  printf("Your PNG library is too old: You have libpng-%s\n",
     PNG_LIBPNG_VER_STRING);
  ThrowBinaryException(CoderError,PNGLibraryTooOld,image_info->filename);
}
static unsigned int WriteMNGImage(const ImageInfo *image_info,Image *image)
{
  return (WritePNGImage(image_info,image));
}
#endif /* PNG_LIBPNG_VER > 95 */
#endif
