NAME

| GraphicsMagick - commandline utilities to create, edit, or convert images

Contents

| Synopsis Description Files and Formats Options Authors Copyright

Synopsis

| gm animate [ options ... ] file [ [ options ... ] file ... ] gm composite [ options ... ] image composite [ mask ] composited gm conjure [ options ] script.msl [ [ options ] script.msl ] gm convert [ [ options ... ] [ input_file ... ] ... [ output_file ] ] gm display [ options ... ] file ... [ [options ... ]file ... ] gm identify file [ file ... ] gm import [ options ... ] file gm mogrify [ options ... ] file ... gm montage [ options ... ] file [ [ options ... ] file ... ] output_file

Description

| GraphicsMagick provides a suite of commandline utilities for creating, converting, editing, and displaying images: Display is a machine architecture independent image processing and display program. It can display an image on any workstation display running an X server. Import reads an image from any visible window on an X server and outputs it as an image file. You can capture a single window, the entire screen, or any rectangular portion of the screen. Montage creates a composite by combining several separate images. The images are tiled on the composite image with the name of the image optionally appearing just below the individual tile. Convert converts an input file using one image format to an output file with a differing image format. Mogrify transforms an image or a sequence of images. These transforms include image scaling, image rotation, color reduction, and others. The transmogrified image overwrites the original image. Identify describes the format and characteristics of one or more image files. It will also report if an image is incomplete or corrupt. Composite composites images to create new images. Conjure interprets and executes scripts in the Magick Scripting Language (MSL). The GraphicsMagick utilities recognize the following image formats:

Name | Mode | Description
8BIM | *rw- | Photoshop resource format
AFM | *r-- | TrueType font
APP1 | *rw- | Photoshop resource format
ART | *r-- | PF1: 1st Publisher
AVI | *r-- | Audio/Visual Interleaved
AVS | *rw+ | AVS X image
BIE | *rw- | Joint Bi-level Image experts Group
|  | interchange format
BMP | *rw+ | Microsoft Windows bitmap image
CAPTION | *r+ | Caption (requires separate size info)
CMYK | *rw- | Raw cyan, magenta, yellow, and black
|  | samples (8 or 16 bits, depending on
|  | the image depth)
CMYKA | *rw- | Raw cyan, magenta, yellow, black, and
|  | matte samples (8 or 16 bits, depending
|  | on the image depth)
CUT | *r-- | DR Halo
DCM | *r-- | Digital Imaging and Communications in
|  | Medicine image
DCX | *rw+ | ZSoft IBM PC multi-page Paintbrush
DIB | *rw+ | Microsoft Windows bitmap image
DPS | *r-- | Display PostScript
DPX | *r-- | Digital Moving Picture Exchange
EPDF | *rw- | Encapsulated Portable Document Format
EPI | *rw- | Adobe Encapsulated PostScript
|  | Interchange format
EPS | *rw- | Adobe Encapsulated PostScript
EPS2 | *-w- | Adobe Level II Encapsulated PostScript
EPS3 | *-w- | Adobe Level III Encapsulated PostScript
EPSF | *rw- | Adobe Encapsulated PostScript
EPSI | *rw- | Adobe Encapsulated PostScript
|  | Interchange format
EPT | *rw- | Adobe Encapsulated PostScript with TIFF
|  | preview
FAX | *rw+ | Group 3 FAX
FILE | *r-- | Uniform Resource Locator
FITS | *rw- | Flexible Image Transport System
FPX | *rw- | FlashPix Format
FTP | *r-- | Uniform Resource Locator
G3 | *rw- | Group 3 FAX
GIF | *rw+ | CompuServe graphics interchange format
GIF87 | *rw- | CompuServe graphics interchange format
|  | (version 87a)
GRADIENT | *r-- | Gradual passing from one shade to
|  | another
GRANITE | *r-- | Granite texture
GRAY | *rw+ | Raw gray samples (8 or 16 bits,
|  | depending on the image depth)
H | *rw- | Internal format
HDF | -rw+ | Hierarchical Data Format
HISTOGRAM | *-w- | Histogram of the image
HTM | *-w- | Hypertext Markup Language and a
|  | client-side image map
HTML | *-w- | Hypertext Markup Language and a
|  | client-side image map
HTTP | *r-- | Uniform Resource Locator
ICB | *rw+ | Truevision Targa image
ICM | *rw- | ICC Color Profile
ICO | *r-- | Microsoft icon
ICON | *r-- | Microsoft icon
IMPLICIT | *--- |
IPTC | *rw- | IPTC Newsphoto
JBG | *rw+ | Joint Bi-level Image experts Group
|  | interchange format
JBIG | *rw+ | Joint Bi-level Image experts Group
|  | interchange format
JP2 | *rw- | JPEG-2000 JP2 File Format Syntax
JPC | *rw- | JPEG-2000 Code Stream Syntax
JPEG | *rw- | Joint Photographic Experts Group
|  | JFIF format
JPG | *rw- | Joint Photographic Experts Group
|  | JFIF format
LABEL | *r-- | Text image format
LOGO | *rw- | GraphicsMagick Logo
M2V | *rw+ | MPEG-2 Video Stream
MAP | *rw- | Colormap intensities (8 or 16 bits,
|  | depending on the image depth) and
|  | indices (8 or 16 bits, depending
|  | on whether colors exceeds 256).
MAT | *-w+ | MATLAB image format
MATTE | *-w+ | MATTE format
MIFF | *rw+ | Magick image format
MNG | *rw+ | Multiple-image Network Graphics
MONO | *rw- | Bi-level bitmap in least-significant-
|  | -byte-first order
MPC | -rw- | Magick Persistent Cache image format
MPEG | *rw+ | MPEG-1 Video Stream
MPG | *rw+ | MPEG-1 Video Stream
MPR | *r-- | Magick Persistent Registry
MSL | *r-- | Magick Scripting Language
MTV | *rw+ | MTV Raytracing image format
MVG | *rw- | Magick Vector Graphics
NETSCAPE | *r-- | Netscape 216 color cube
NULL | *r-- | Constant image of uniform color
OTB | *rw- | On-the-air bitmap
P7 | *rw+ | Xv thumbnail format
PAL | *rw- | 16bit/pixel interleaved YUV
PALM | *rw- | Palm Pixmap format
PBM | *rw+ | Portable bitmap format (black and white)
PCD | *rw- | Photo CD
PCDS | *rw- | Photo CD
PCL | *-w- | Page Control Language
PCT | *rw- | Apple Macintosh QuickDraw/PICT
PCX | *rw- | ZSoft IBM PC Paintbrush
PDB | *r-- | Pilot Image Format
PDF | *rw+ | Portable Document Format
PFA | *r-- | TrueType font
PFB | *r-- | TrueType font
PFM | *r-- | TrueType font
PGM | *rw+ | Portable graymap format (gray scale)
PICON | *rw- | Personal Icon
PICT | *rw- | Apple Macintosh QuickDraw/PICT
PIX | *r-- | Alias/Wavefront RLE image format
PLASMA | *r-- | Plasma fractal image
PM | *rw- | X Windows system pixmap (color)
PNG | *rw- | Portable Network Graphics
PNM | *rw+ | Portable anymap
PPM | *rw+ | Portable pixmap format (color)
PREVIEW | *-w- | Show a preview an image enhancement,
|  | effect, or f/x
PS | *rw+ | Adobe PostScript
PS2 | *-w+ | Adobe Level II PostScript
PS3 | *-w+ | Adobe Level III PostScript
PSD | *rw- | Adobe Photoshop bitmap
PTIF | *rw- | Pyramid encoded TIFF
PWP | *r-- | Seattle Film Works
RAS | *rw+ | SUN Rasterfile
RGB | *rw+ | Raw red, green, and blue samples (8 or
|  | 16 bits, depending on the image depth)
RGBA | *rw+ | Raw red, green, blue, and matte samples
|  | (8 or 16 bits, depending on the image
|  | depth)
RLA | *r-- | Alias/Wavefront image
RLE | *r-- | Utah Run length encoded image
ROSE | *rw- | 70x46 Truecolor test image
SCT | *r-- | Scitex HandShake
SFW | *r-- | Seattle Film Works
SGI | *rw+ | Irix RGB image
SHTML | *-w- | Hypertext Markup Language and a
|  | client-side image map
STEGANO | *r-- | Steganographic image
SUN | *rw+ | SUN Rasterfile
SVG | *rw+ | Scalable Vector Gaphics
TEXT | *rw+ | Raw text
TGA | *rw+ | Truevision Targa image
TIF | *rw+ | Tagged Image File Format
TIFF | *rw+ | Tagged Image File Format
TILE | *r-- | Tile image with a texture
TIM | *r-- | PSX TIM
TTF | *r-- | TrueType font
TXT | *rw+ | Raw text
UIL | *-w- | X-Motif UIL table
UYVY | *rw- | 16bit/pixel interleaved YUV
VDA | *rw+ | Truevision Targa image
VICAR | *rw- | VICAR rasterfile format
VID | *rw+ | Visual Image Directory
VIFF | *rw+ | Khoros Visualization image
VST | *rw+ | Truevision Targa image
WBMP | *rw- | Wireless Bitmap (level 0) image
WMF | *r-- | Windows Metafile
WPG | *r-- | Word Perfect Graphics
X | *rw- | X Image
XBM | *rw- | X Windows system bitmap (black
|  | and white)
XC | *r-- | Constant image uniform color
XCF | *r-- | GIMP image
XML | *r-- | Scalable Vector Gaphics
XPM | *rw- | X Windows system pixmap (color)
XV | *rw+ | Khoros Visualization image
XWD | *rw- | X Windows system window dump (color)
YUV | *rw- | CCIR 601 4:1:1
Modes: |  |
| * | Native blob support
| r | Read
| w | Write
| + | Multi-image
Support for some of these formats require additional programs or libraries. README tells where to find this software. Note, a format delineated with `+` means that if more than one image is specified, it is composited into a single multi-image file. Use +adjoin if you want a single image produced for each frame. Your installation might not support all of the formats in the list. To get an up-to-date listing of the formats supported by your particular configuration, run `"convert -list format"`. Raw images are expected to have one byte per pixel unless GraphicsMagick is compiled in the default 16-bit mode or in 32-bit mode. Here, the raw data is expected to be stored two bytes per pixel in most-significant-byte-first order. You can tell if GraphicsMagick was compiled in 16-bit mode by typing "convert" without any options, and looking for "Q:16" in the first line of output.

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Files and Formats

| By default, the image format is determined by its magic number, i.e., the first few bytes of the file. To specify a particular image format, precede the filename with an image format name and a colon (i.e.ps:image) or specify the image type as the filename suffix. The magic number takes precedence over the filename suffix and the prefix takes precedence over the magic number and the suffix in input files. The prefix takes precedence over the filename suffix in output files. To read the "built-in" formats (GRANITE, H, LOGO, NETSCAPE, PLASMA, and ROSE) use a prefix (including the colon) without a filename or suffix. To read the XC format, follow the colon with a color specification. To read the CAPTION format, follow the colon with a text string or with a filename prefixed with the at symbol (@). When you specify X as your image type, the filename has special meaning. It specifies an X window by id, name, or root. If no filename is specified, the window is selected by clicking the mouse in the desired window. Specify input_file as - for standard input, output_file as - for standard output. If input_file has the extension .Z or .gz, the file is uncompressed with uncompress or gunzip respectively. If output_file has the extension .Z or .gz, the file is compressed using with compress or gzip respectively. Finally, when running on platforms that allow it, precede the image file name with | to pipe to or from a system command (this feature is not available on VMS, Win32 and Macintosh platforms). Use a backslash or quotation marks to prevent your shell from interpreting the |. Use an optional index enclosed in brackets after an input file name to specify a desired subimage of a multi-resolution image format like Photo CD (e.g. `"img0001.pcd[4]"`) or a range for MPEG images (e.g. `"video.mpg[50-75]"`). A subimage specification can be disjoint (e.g. `"image.tiff[2,7,4]"`). For raw images, specify a subimage with a geometry (e.g. `-size 640x512` `"image.rgb[320x256+50+50]"`). Surround the image name with quotation marks to prevent your shell from interpreting the square brackets. Single images are written with the filename you specify. However, multi-part images (e.g., a multi-page PostScript document with +adjoin specified) are written with the filename followed by a period (.) and the scene number. You can change this behavior by embedding a `%d, %0Nd, %o, %0No, %x,` or `%0Nx` printf format specification in the file name. For example,
        image%02d.miff
writes files image00.miff, image01.miff, etc. When running a commandline utility, you can prepend an at sign `@` to a filename to read a list of image filenames from that file. This is convenient in the event you have too many image filenames to fit on the command line.

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Options

| Options are processed in command line order. Any option you specify on the command line remains in effect for the set of images that follows, until the set is terminated by the appearance of any option or -noop. Some options only affect the decoding of images and others only the encoding. The latter can appear after the final group of input images. This is a combined list of the commandline options used by the GraphicsMagick utilities (animate, composite, convert, display, identify, import, mogrify and montage). In this document, angle brackets ("<>") enclose variables and curly brackets ("{}") enclose optional parameters. For example, "-fuzz <distance>{%}" means you can use the option `"-fuzz 10"` or `"-fuzz 2%"`.
| -adjoin
| join images into a single multi-image file
| By default, all images of an image sequence are stored in the same file. However, some formats (e.g. JPEG) do not support more than one image and are saved to separate files. Use +adjoin to force this behavior.
| -affine <matrix>
| drawing transform matrix
| This option provides a transform matrix `{sx,rx,ry,sy,tx,ty}` for use by subsequent -draw or -transform options.
| -antialias
| remove pixel aliasing
| By default antialiasing algorithms are used when drawing objects (e.g. lines) or rendering vector formats (e.g. WMF and Postscript). Use +antialias to disable use of antialiasing algorithms. Reasons to disable antialiasing
include avoiding increasing colors in the image, or improving rendering speed.
| -append
| append a set of images
| This option creates a single image where the images in the original set are stacked top-to-bottom. If they are not of the same width, any narrow images will be expanded to fit using the background color. Use +append to stack images left-to-right. The set of images is terminated by the appearance of any option. If the -append option appears after all of the input images, all images are appended.
| -authenticate <string>
| decrypt image with this password
| Use this option to supply a password for decrypting an image or an image sequence, if it is being read from a format such as PDF that supports encryption. Encrypting images being written is not supported.
| -average
| average a set of images
| The set of images is terminated by the appearance of any option. If the -average option appears after all of the input images, all images are averaged.
| -backdrop <color>
| display the image centered on a backdrop.
| This backdrop covers the entire workstation screen and is useful for hiding other X window activity while viewing the image. The color of the backdrop is specified as the background color. The color is specified using the format described in the "Color Names" section of X(1). Refer to X Resources for details.
| -background <color>
| the background color
| The color is specified using the format described in the "Color Names" section of X(1).
| -blue-primary <x>,<y>
| blue chromaticity primary point
| -blur <radius>x<sigma>
| blur the image with a Gaussian operator
| Blur with the given radius and standard deviation (sigma).
| -border <width>x<height>
| surround the image with a border of color
| See -geometry for details about the geometry specification.
| -bordercolor <color>
| the border color
| The color is specified using the format described in the "Color Names" section of X(1).
| -borderwidth <geometry>
| the border width
| -box <color>
| set the color of the annotation bounding box
| The color is specified using the format described in the "Color Names" section of X(1).
| See -draw for further details.
| -cache <threshold>
| megabytes of memory available to the pixel cache
| This option is deprecated. It has been replaced by the -limit option.
| -channel <type>
| the type of channel
| Choose from: Red, Green, Blue, Opacity, Cyan, Magenta, Yellow, or Black.
| Use this option to extract a particular channel from the image. Matte, for example, is useful for extracting the opacity values from an image.
| -charcoal <factor>
| simulate a charcoal drawing
| -chop <width>x<height>{+-}<x>{+-}<y>{%}
| remove pixels from the interior of an image
| Width and height give the number of columns and rows to remove, and x and y are offsets that give the location of the leftmost column and topmost row to remove.
| The x offset normally specifies the leftmost column to remove. If the -gravity option is present with NorthEast, East, or SouthEast gravity, it gives the distance leftward from the right edge of the image to the rightmost column to remove. Similarly, the y offset normally specifies the topmost row to remove, but if the -gravity option is present with SouthWest, South, or SouthEast gravity, it specifies the distance upward from the bottom edge of the image to the bottom row to remove.
| The -chop option removes entire rows and columns, and moves the remaining corner blocks leftward and upward to close the gaps.
| -clip
| apply the clipping path, if one is present
| If a clipping path is present, it will be applied to subsequent operations.
| For example, if you type the following command:
         gm convert -clip -negate cockatoo.tif negated.tif
| only the pixels within the clipping path are negated.
| The -clip feature requires the XML library. If the XML library is not present, the option is ignored.
| -coalesce
| merge a sequence of images
| Each image N in the sequence after Image 0 is replaced with the image created by flattening images 0 through N.
| The set of images is terminated by the appearance of any option. If the -coalesce option appears after all of the input images, all images are coalesced.
| -colorize <value>
| colorize the image with the pen color
| Specify the amount of colorization as a percentage. You can apply separate colorization values to the red, green, and blue channels of the image with a colorization value list delineated with slashes (e.g. 0/0/50).
| -colormap <type>
| define the colormap type
| Choose between shared or private.
| This option only applies when the default X server visual is PseudoColor or GRAYScale. Refer to -visual for more details. By default, a shared colormap is allocated. The image shares colors with other X clients. Some image colors could be approximated, therefore your image may look very different than intended. Choose Private and the image colors appear exactly as they are defined. However, other clients may go technicolor when the image colormap is installed.
| -colors <value>
| preferred number of colors in the image
| The actual number of colors in the image may be less than your request, but never more. Note, this is a color reduction option. Images with less unique colors than specified with this option will have any duplicate or unused colors removed. Refer to quantize for more details.
| Note, options -dither, -colorspace, and -treedepth affect the color reduction algorithm.
| -colorspace <value>
| the type of colorspace
| Choices are: GRAY, OHTA, RGB, Transparent, XYZ, YCbCr, YIQ, YPbPr, YUV, or CMYK.
| Color reduction, by default, takes place in the RGB color space. Empirical evidence suggests that distances in color spaces such as YUV or YIQ correspond to perceptual color differences more closely than do distances in RGB space. These color spaces may give better results when color reducing an image. Refer to quantize for more details.
| The Transparent color space behaves uniquely in that it preserves the matte channel of the image if it exists.
| The -colors or -monochrome option is required for this option to take effect.
| -comment <string>
| annotate an image with a comment
| Use this option to assign a specific comment to the image, when writing to an image format that supports comments. You can include the image filename, type, width, height, or other image attribute by embedding special format characters listed under the -format option.
| For example,
         -comment "%m:%f %wx%h"
| produces an image comment of MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.
| If the first character of string is @, the image comment is read from a file titled by the remaining characters in the string.
| -compose <operator>
| the type of image composition
| [This option is not used by convert or mogrify but this section is included because it describes the composite operators that are used by the -draw option.]
| -compress <type>
| the type of image compression
| Choices are: None, BZip, Fax, Group4, JPEG, Lossless, LZW, RLE or Zip.
| Specify +compress to store the binary image in an uncompressed format. The default is the compression type of the specified image file.
| If LZW compression is specified but LZW compression has not been enabled, the image data will be written in an uncompressed LZW format that can be read by LZW decoders. This may result in larger-than-expected GIF files.
| "Lossless" refers to lossless JPEG, which is only available if the JPEG library has been patched to support it.
| Use the -quality option to set the compression level to be used by JPEG, PNG, MIFF, and MPEG encoders. Use the -sampling-factor option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders for downsampling the chroma channels.
| -contrast
| enhance or reduce the image contrast
| This option enhances the intensity differences between the lighter and darker elements of the image. Use -contrast to enhance the image or +contrast to reduce the image contrast.
| -crop <width>x<height>{+-}<x>{+-}<y>{%}
| preferred size and location of the cropped image
| See -geometry for details about the geometry specification.
| The width and height give the size of the image that remains after cropping, and x and y are offsets that give the location of the top left corner of the cropped image with respect to the original image. To specify the amount to be removed, use -shave instead.
| To specify a percentage width or height to be removed instead, append %. For example to crop the image by ten percent (five percent on each side of the image), use -crop 10%.
| If the x and y offsets are present, a single image is generated, consisting of the pixels from the cropping region. The offsets specify the location of the upper left corner of the cropping region measured downward and rightward with respect to the upper left corner of the image. If the -gravity option is present with NorthEast, East, or SouthEast gravity, it gives the distance leftward from the right edge of the image to the right edge of the cropping region. Similarly, if the -gravity option is present with SouthWest, South, or SouthEast gravity, the distance is measured upward between the bottom edges.
| If the x and y offsets are omitted, a set of tiles of the specified geometry, covering the entire input image, is generated. The rightmost tiles and the bottom tiles are smaller if the specified geometry extends beyond the dimensions of the input image.
| -cycle <amount>
| displace image colormap by amount
| Amount defines the number of positions each colormap entry is shifted.
| -debug <events>
| enable debug printout
| The `events` parameter specifies which events are to be logged. It can be either `None`, `All`, or a comma-separated list consisting of one or more of the following domains: `Annotate`, `Blob`, `Cache`, `Coder`, `Configure`, `Locale`, `Render`, `Transform`, `X11`, or `User`. For example, to log cache and blob events, use
        gm convert -debug "Cache,Blob" rose: rose.png
| The "User" domain is normally empty, but developers can log "User" events in their private copy of GraphicsMagick.
| Use +debug to turn off all logging.
| -deconstruct
| break down an image sequence into constituent parts
| This option compares each image with the next in a sequence and returns the maximum bounding region of any pixel differences it discovers. This method can undo a coalesced sequence returned by the -coalesce option, and is useful for removing redundant information from a GIF or MNG animation.
| The sequence of images is terminated by the appearance of any option. If the -deconstruct option appears after all of the input images, all images are deconstructed.
| -delay <1/100ths of a second>
| display the next image after pausing
| This option is useful for regulating the animation of image sequences Delay/100 seconds must expire before the display of the next image. The default is no delay between each showing of the image sequence. The maximum delay is 65535.
| You can specify a delay range (e.g. -delay 10-500) which sets the minimum and maximum delay.
| -density <width>x<height>
| vertical and horizontal resolution in pixels of the image
| This option specifies an image density when decoding a PostScript or Portable Document page. The default is 72 dots per inch in the horizontal and vertical direction. This option is used in concert with -page.
| -depth <value>
| depth of the image
| This is the number of bits in a color sample within a pixel. The only acceptable values are 8 or 16. Use this option to specify the depth of raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any image after it has been read.
| -descend
| obtain image by descending window hierarchy
| -despeckle
| reduce the speckles within an image
| -displace <horizontal scale>x<vertical scale>
| shift image pixels as defined by a displacement map
| With this option, composite image is used as a displacement map. Black, within the displacement map, is a maximum positive displacement. White is a maximum negative displacement and middle gray is neutral. The displacement is scaled to determine the pixel shift. By default, the displacement applies in both the horizontal and vertical directions. However, if you specify mask, composite image is the horizontal X displacement and mask the vertical Y displacement.
| -display <host:display[.screen]>
| specifies the X server to contact
| This option is used with convert for obtaining image or font from this X server. See X(1).
| -dispose <method>
| GIF disposal method
| The Disposal Method indicates the way in which the graphic is to be treated after being displayed.
| Here are the valid methods:
        Undefined       No disposal specified.
        None            Do not dispose between frames.
        Background      Overwrite the image area with
                        the background color.
        Previous        Overwrite the image area with
                        what was there prior to rendering
                        the image.
| -dissolve <percent>
| dissolve an image into another by the given percent
| The opacity of the composite image is multiplied by the given percent, then it is composited over the main image.
| -dither
| apply Floyd/Steinberg error diffusion to the image
| The basic strategy of dithering is to trade intensity resolution for spatial resolution by averaging the intensities of several neighboring pixels. Images which suffer from severe contouring when reducing colors can be improved with this option.
| The -colors or -monochrome option is required for this option to take effect.
| Use +dither to turn off dithering and to render PostScript without text or graphic aliasing.
| -draw <string>
| annotate an image with one or more graphic primitives
| Use this option to annotate an image with one or more graphic primitives. The primitives include shapes, text, transformations, and pixel operations. The shape primitives are
         point           x,y
         line            x0,y0 x1,y1
         rectangle       x0,y0 x1,y1
         roundRectangle  x0,y0 x1,y1 wc,hc
         arc             x0,y0 x1,y1 a0,a1
         ellipse         x0,y0 rx,ry a0,a1
         circle          x0,y0 x1,y1
         polyline        x0,y0  ...  xn,yn
         polygon         x0,y0  ...  xn,yn
         Bezier          x0,y0  ...  xn,yn
         path            path specification
         image           operator x0,y0 w,h filename
| The text primitive is
         text            x0,y0 string
| The transformation primitives are
         rotate          degrees
         translate       dx,dy
         scale           sx,sy
         skewX           degrees
         skewY           degrees
| The pixel operation primitives are
         color           x0,y0 method
         matte           x0,y0 method
| The shape primitives are drawn in the color specified in the preceding -stroke option. Except for the line and point primitives, they are filled with the color specified in the preceding -fill option. For unfilled shapes, use `-fill none`
.
| Point requires a single coordinate.
| Line requires a start and end coordinate.
| Rectangle expects an upper left and lower right coordinate.
| RoundRectangle has the upper left and lower right coordinates and the width and height of the corners.
| Circle has a center coordinate and a coordinate for the outer edge.
| Use Arc to inscribe an elliptical arc within a rectangle. Arcs require a start and end point as well as the degree of rotation (e.g. 130,30 200,100 45,90).
| Use Ellipse to draw a partial ellipse centered at the given point with the x-axis and y-axis radius and start and end of arc in degrees (e.g. 100,100 100,150 0,360).
| Finally, polyline and polygon require three or more coordinates to define its boundaries. Coordinates are integers separated by an optional comma. For example, to define a circle centered at 100,100 that extends to 150,150 use:
         -draw 'circle 100,100 150,150'
| Paths (See Paths) represent an outline of an object which is defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a curve using a cubic Bezier), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with subpaths, each consisting of a single moveto followed by one or more line or curve operations) are possible to allow effects such as "donut holes" in objects.
| Use image to composite an image with another image. Follow the image keyword with the composite operator, image location, image size, and filename:
         -draw 'image Over 100,100 225,225 image.jpg'
| You can use 0,0 for the image size, which means to use the actual dimensions found in the image header. Otherwise, it will be scaled to the given dimensions. See -compose for a description of the composite operators.
| Use text to annotate an image with text. Follow the text coordinates with a string. If the string has embedded spaces, enclose it in double quotes. Optionally you can include the image filename, type, width, height, or other image attribute by embedding special format character. See -comment for details.
| For example,
         -draw 'text 100,100 "%m:%f %wx%h"'
| annotates the image with `MIFF:bird.miff 512x480` for an image titled `bird.miff` and whose width is 512 and height is 480.
| If the first character of string is @, the text is read from a file titled by the remaining characters in the string.
| Rotate rotates subsequent shape primitives and text primitives about the origen of the main image. If the -region option precedes the -draw option, the origen for transformations is the upper left corner of the region.
| Translate translates them.
| Scale scales them.
| SkewX and SkewY skew them with respect to the origen of the main image or the region.
| The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the -affine option. Transformations are cumulative within the -draw option. The initial affine matrix is not affected; that matrix is only changed by the appearance of another -affine option. If another -draw option appears, the current affine matrix is reinitialized from the initial affine matrix.
| Use color to change the color of a pixel to the fill color (see -fill). Follow the pixel coordinate with a method:
         point
         replace
         floodfill
         filltoborder
         reset
| Consider the target pixel as that specified by your coordinate. The point method recolors the target pixel. The replace method recolors any pixel that matches the color of the target pixel. Floodfill recolors any pixel that matches the color of the target pixel and is a neighbor, whereas filltoborder recolors any neighbor pixel that is not the border color. Finally, reset recolors all pixels.
| Use matte to the change the pixel matte value to transparent. Follow the pixel coordinate with a method (see the color primitive for a description of methods). The point method changes the matte value of the target pixel. The replace method changes the matte value of any pixel that matches the color of the target pixel. Floodfill changes the matte value of any pixel that matches the color of the target pixel and is a neighbor, whereas filltoborder changes the matte value of any neighbor pixel that is not the border color (-bordercolor). Finally reset changes the matte value of all pixels.
| You can set the primitive color, font, and font bounding box color with -fill, -font, and -box respectively. Options are processed in command line order so be sure to use these options before the -draw option.
| -edge <radius>
| detect edges within an image
| -emboss
| emboss an image
| -encoding <type>
| specify the text encoding
| Choose from AdobeCustom, AdobeExpert, AdobeStandard, AppleRoman, BIG5, GB2312, Latin 2, None, SJIScode, Symbol, Unicode, Wansung.
| -endian <type>
| specify endianness (MSB or LSB) of output image
| Use +endian to revert to unspecified endianness.
| -enhance
| apply a digital filter to enhance a noisy image
| -equalize
| perform histogram equalization to the image
| -fill <color>
| color to use when filling a graphic primitive
| The color is specified using the format described in the "Color Names" section of X(1).
| See -draw for further details.
| -filter <type>
| use this type of filter when resizing an image
| Use this option to affect the resizing operation of an image (see -geometry). Choose from these filters:
         Point
         Box
         Triangle
         Hermite
         Hanning
         Hamming
         Blackman
         Gaussian
         Quadratic
         Cubic
         Catrom
         Mitchell
         Lanczos
         Bessel
         Sinc
| The default filter is Lanczos
| -flatten
| flatten a sequence of images
| The sequence of images is replaced by a single image created by composing each image after the first over the first image.
| The sequence of images is terminated by the appearance of any option. If the -flatten option appears after all of the input images, all images are flattened.
| -flip
| create a "mirror image"
| reflect the scanlines in the vertical direction.
| -flop
| create a "mirror image"
| reflect the scanlines in the horizontal direction.
| -font <name>
| use this font when annotating the image with text
| You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example, `Arial.ttf` is a TrueType font, `ps:helvetica` is PostScript, and `x:fixed` is OPTION1.
| -foreground <color>
| define the foreground color
| The color is specified using the format described in the "Color Names" section of X(1).
| -format <type>
| the image format type
| This option will convert any image to the image format you specify. See GraphicsMagick(1) for a list of image format types supported by GraphicsMagick.
| By default the file is written to its original name. However, if the filename extension matches a supported format, the extension is replaced with the image format type specified with -format. For example, if you specify tiff as the format type and the input image filename is image.gif, the output image filename becomes image.tiff.
| -format <string>
| output formatted image characteristics
| Use this option to print information about the image in a format of your choosing. You can include the image filename, type, width, height, Exif data, or other image attributes by embedding special format characters:
         %b   file size
         %c   comment
         %d   directory
         %e   filename extension
         %f   filename
         %h   height
         %i   input filename
         %k   number of unique colors
         %l   label
         %m   magick
         %n   number of scenes
         %o   output filename
         %p   page number
         %q   quantum depth
         %s   scene number
         %t   top of filename
         %u   unique temporary filename
         %w   width
         %x   x resolution
         %y   y resolution
         %#   signature
         %%   percent sign
         \n   newline
         \r   carriage return
| For example,
         -format "%m:%f %wx%h"
| displays MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.
| If the first character of string is @, the format is read from a file titled by the remaining characters in the string.
| You can also use the following special formatting syntax to print Exif information contained in the file:
         %[EXIF:<tag>]
| Where "<tag>" can be one of the following:
         *  (print all Exif tags, in keyword=data format)
         !  (print all Exif tags, in tag_number data format)
         #hhhh (print data for Exif tag #hhhh)
         ImageWidth
         ImageLength
         BitsPerSample
         Compression
         PhotometricInterpretation
         FillOrder
         DocumentName
         ImageDescription
         Make
         Model
         StripOffsets
         Orientation
         SamplesPerPixel
         RowsPerStrip
         StripByteCounts
         XResolution
         YResolution
         PlanarConfiguration
         ResolutionUnit
         TransferFunction
         Software
         DateTime
         Artist
         WhitePoint
         PrimaryChromaticities
         TransferRange
         JPEGProc
         JPEGInterchangeFormat
         JPEGInterchangeFormatLength
         YCbCrCoefficients
         YCbCrSubSampling
         YCbCrPositioning
         ReferenceBlackWhite
         CFARepeatPatternDim
         CFAPattern
         BatteryLevel
         Copyright
         ExposureTime
         FNumber
         IPTC/NAA
         ExifOffset
         InterColorProfile
         ExposureProgram
         SpectralSensitivity
         GPSInfo
         ISOSpeedRatings
         OECF
         ExifVersion
         DateTimeOriginal
         DateTimeDigitized
         ComponentsConfiguration
         CompressedBitsPerPixel
         ShutterSpeedValue
         ApertureValue
         BrightnessValue
         ExposureBiasValue
         MaxApertureValue
         SubjectDistance
         MeteringMode
         LightSource
         Flash
         FocalLength
         MakerNote
         UserComment
         SubSecTime
         SubSecTimeOriginal
         SubSecTimeDigitized
         FlashPixVersion
         ColorSpace
         ExifImageWidth
         ExifImageLength
         InteroperabilityOffset
         FlashEnergy
         SpatialFrequencyResponse
         FocalPlaneXResolution
         FocalPlaneYResolution
         FocalPlaneResolutionUnit
         SubjectLocation
         ExposureIndex
         SensingMethod
         FileSource
         SceneType
| Surround the format specification with quotation marks to prevent your shell from misinterpreting any spaces and square brackets.
| -frame <width>x<height>+<outer bevel width>+<inner bevel width>
| surround the image with an ornamental border
| See -geometry for details about the geometry specification. The -frame option is not affected by the -gravity option.
| The color of the border is specified with the -mattecolor command line option.
| -frame
| include the X window frame in the imported image
| -fuzz <distance>{%}
| colors within this distance are considered equal
| A number of algorithms search for a target color. By default the color must be exact. Use this option to match colors that are close to the target color in RGB space. For example, if you want to automatically trim the edges of an image with -trim but the image was scanned and the target background color may differ by a small amount. This option can account for these differences.
| The distance can be in absolute intensity units or, by appending "%", as a percentage of the maximum possible intensity (255 or 65535).
| -gamma <value>
| level of gamma correction
| The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from 0.8 to 2.3.
| You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delineated with slashes (e.g., 1.7/2.3/1.2).
| Use +gamma value to set the image gamma level without actually adjusting the image pixels. This option is useful if the image is of a known gamma but not set as an image attribute (e.g. PNG images).
| -Gaussian <radius>x<sigma>
| blur the image with a Gaussian operator
| Use the given radius and standard deviation (sigma).
| -geometry <width>x<height>{+-}<x>{+-}<y>{%}{@} {!}{<}{>}
| preferred size and location of the Image window.
| By default, the window size is the image size and the location is chosen by you when it is mapped.
| By default, the width and height are maximum values. That is, the image is expanded or contracted to fit the width and height value while maintaining the aspect ratio of the image. Append an exclamation point to the geometry to force the image size to exactly the size you specify. For example, if you specify `640x480!` the image width is set to 640 pixels and height to 480.
| If only the width is specified, the width assumes the value and the height is chosen to maintain the aspect ratio of the image. Similarly, if only the height is specified (e.g., `-geometry x256`), the width is chosen to maintain the aspect ratio.
| To specify a percentage width or height instead, append %. The image size is multiplied by the width and height percentages to obtain the final image dimensions. To increase the size of an image, use a value greater than 100 (e.g. 125%). To decrease an image's size, use a percentage less than 100.
| Use `@` to specify the maximum area in pixels of an image.
| Use `>` to change the dimensions of the image only if its width or height exceeds the geometry specification. `<` resizes the image only if both of its dimensions are less than the geometry specification. For example, if you specify `'640x480>'` and the image size is 256x256, the image size does not change. However, if the image is 512x512 or 1024x1024, it is resized to 480x480. Enclose the geometry specification in quotation marks to prevent the `<` or `>` from being interpreted by your shell as a file redirection.
| When used with animate and display, offsets are handled in the same manner as in X(1) and the -gravity option is not used. If the x is negative, the offset is measured leftward from the right edge of the screen to the right edge of the image being displayed. Similarly, negative y is measured between the bottom edges. The offsets are not affected by "%"; they are always measured in pixels.
| When used as a composite option, -geometry gives the dimensions of the image and its location with respect to the composite image. If the -gravity option is present with NorthEast, East, or SouthEast gravity, the x represents the distance from the right edge of the image to the right edge of the composite image. Similarly, if the -gravity option is present with SouthWest, South, or SouthEast gravity, y is measured between the bottom edges. Accordingly, a positive offset will never point in the direction outside of the image. The offsets are not affected by "%"; they are always measured in pixels. To specify the dimensions of the composite image, use the -resize option.
| When used as a convert, import or mogrify option, -geometry is synonymous with -resize and specifies the size of the output image. The offsets, if present, are ignored.
| When used as a montage option, -geometry specifies the image size and border size for each tile; default is 256x256+0+0. Negative offsets (border dimensions) are meaningless. The -gravity option affects the placement of the image within the tile; the default gravity for this purpose is Center. If the "%" sign appears in the geometry specification, the tile size is the specified percentage of the original dimensions of the first tile. To specify the dimensions of the montage, use the -resize option.
| -gravity <type>
| direction primitive gravitates to when annotating the image.
| Choices are: NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast.
| The direction you choose specifies where to position the text or other graphic primitive when annotating the image. For example Center gravity forces the text to be centered within the image. By default, the image gravity is NorthWest. See -draw for more details about graphic primitives.
| The -gravity option is also used in concert with the -geometry option and other options that take <geometry> as a parameter, such as the -crop option. See -geometry for details of how the -gravity option interacts with the <x> and <y> parameters of a geometry specification.
| When used as an option to composite, -gravity gives the direction that the image gravitates within the composite.
| When used as an option to montage, -gravity gives the direction that an image gravitates within a tile. The default gravity is Center for this purpose.
| -green-primary <x>,<y>
| green chromaticity primary point
| -help
| print usage instructions
| -iconGeometry <geometry>
| specify the icon geometry
| Offsets, if present in the geometry specification, are handled in the same manner as the -geometry option, using X11 style to handle negative offsets.
| -iconic
| iconic animation
| -immutable
| make image immutable
| -implode <factor>
| implode image pixels about the center
| -intent <type>
| use this type of rendering intent when managing the image color
| Use this option to affect the the color management operation of an image (see -profile). Choose from these intents: Absolute, Perceptual, Relative, Saturation
| The default intent is undefined.
| -interlace <type>
| the type of interlacing scheme
| Choices are: None, Line, Plane, or Partition. The default is None.
| This option is used to specify the type of interlacing scheme for raw image formats such as RGB or YUV.
| None means do not interlace (RGBRGBRGBRGBRGBRGB...),
| Line uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and
| Plane uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).
| Partition is like plane except the different planes are saved to individual files (e.g. image.R, image.G, and image.B).
| Use Line or Plane to create an interlaced PNG or GIF or progressive JPEG image.
| -label <name>
| assign a label to an image
| Use this option to assign a specific label to the image. Optionally you can include the image filename, type, width, height, or other image attribute by embedding special format character. See -comment for details.
| For example,
         -label "%m:%f %wx%h"
| produces an image label of MIFF:bird.miff 512x480 for an image titled bird.miff and whose width is 512 and height is 480.
| If the first character of string is @, the image label is read from a file titled by the remaining characters in the string.
| When converting to PostScript, use this option to specify a header string to print above the image. Specify the label font with -font.
| -lat <radius>x<sigma>{+-}<offset>{%}
| perform local adaptive thresholding
| Perform local adaptive thresholding using the specified radius, sigma, and offset. The offset is a distance in sample space from the mean, as an absolute integer ranging from 0 to the maximum sample value or as a percentage. For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.
| -level <value>
| adjust the level of image contrast
| Give three point values delineated with commas: black, mid, and white (e.g. 10,1.0,65000). The white and black points range from 0 to MaxRGB and mid ranges from 0 to 10.
| -limit <type> <value>
| Disk, Map, or Memory resource limit
| The value is in Megabytes. By default all are unlimited. When the limit is reached, GraphicsMagick will fail in some fashion, or take compensating actions if possible. For example, `-limit memory 32 -limit map 64` limits memory When the pixel cache reaches the memory limit it uses memory mapping. When that limit is reached it goes to disk. If disk has a hard limit, the program will fail.
| -linewidth
| the line width for subsequent draw operations
| -list <type>
| the type of list
| Choices are: Delegate, Format, Magic, Module, or Type.
| This option lists entries from the GraphicsMagick configuration files.
| -log <string>
| This option specifies the format for the log printed when the -debug option is active.
| You can display the following components by embedding special format characters:
         %d   domain
         %e   event
         %f   function
         %l   line
         %m   module
         %p   process ID
         %r   real CPU time
         %t   wall clock time
         %u   user CPU time
         %%   percent sign
         \n   newline
         \r   carriage return
| For example:
        gm convert -debug coders -log "%u %m:%l %e" in.gif out.png
| The default behavior is to print all of the components.
| -loop <iterations>
| add Netscape loop extension to your GIF animation
| A value other than zero forces the animation to repeat itself up to iterations times.
| -magnify <factor>
| magnify the image
| -map <filename>
| choose a particular set of colors from this image
| [convert or mogrify]
| By default, color reduction chooses an optimal set of colors that best represent the original image. Alternatively, you can choose a particular set of colors from an image file with this option.
| Use +map to reduce all images in the image sequence that follows to a single optimal set of colors that best represent all the images. The sequence of images is terminated by the appearance of any option. If the +map option appears after all of the input images, all images are mapped.
| -map <type>
| display image using this type.
| [animate or display]
| Choose from these Standard Colormap types:
         best
         default
         gray
         red
         green
         blue
| The X server must support the Standard Colormap you choose, otherwise an error occurs. Use list as the type and display searches the list of colormap types in top-to-bottom order until one is located. See xstdcmap(1) for one way of creating Standard Colormaps.
| -mask <filename>
| Specify a clipping mask
| The image read from the file is used as a clipping mask. It must have the same dimensions as the image being masked.
| If the mask image contains an opacity channel, the opacity of each pixel is used to define the mask. Otherwise, the intensity (gray level) of each pixel is used.
| Use +mask to remove the clipping mask.
| It is not necessary to use -clip to activate the mask; -clip is implied by -mask.
| -matte
| store matte channel if the image has one
| If the image does not have a matte channel, create an opaque one.
| Use +matte to ignore the matte channel and to avoid writing a matte channel in the output file.
| -mattecolor <color>
| specify the color to be used with the -frame option
| The color is specified using the format described in the "Color Names" section of X(1).
| -median <radius>
| apply a median filter to the image
| -mode <value>
| mode of operation
| -modulate <value>
| vary the brightness, saturation, and hue of an image
| Specify the percent change in brightness, the color saturation, and the hue separated by commas. For example, to increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use: -modulate 120,90.
| -monochrome
| transform the image to black and white
| -morph <frames>
| morphs an image sequence
| Both the image pixels and size are linearly interpolated to give the appearance of a meta-morphosis from one image to the next.
| The sequence of images is terminated by the appearance of any option. If the -morph option appears after all of the input images, all images are morphed.
| -mosaic
| create a mosaic from an image sequence
| The -page option is used to locate the images within the mosaic.
| The sequence of images is terminated by the appearance of any option. If the -mosaic option appears after all of the input images, all images are included in the mosaic.
| -name
| name an image
| -negate
| replace every pixel with its complementary color
| The red, green, and blue intensities of an image are negated. White becomes black, yellow becomes blue, etc. Use +negate to only negate the grayscale pixels of the image.
| -noise <radius|type>
| add or reduce noise in an image
| The principal function of noise peak elimination filter is to smooth the objects within an image without losing edge information and without creating undesired structures. The central idea of the algorithm is to replace a pixel with its next neighbor in value within a pixel window, if this pixel has been found to be noise. A pixel is defined as noise if and only if this pixel is a maximum or minimum within the pixel window.
| Use radius to specify the width of the neighborhood.
| Use +noise followed by a noise type to add noise to an image. Choose from these noise types:
         Uniform
         Gaussian
         Multiplicative
         Impulse
         Laplacian
         Poisson
| -noop
| NOOP (no option)
| The -noop option can be used to terminate a group of images and reset all options to their default values, when no other option is desired.
| -normalize
| transform image to span the full range of color values
| This is a contrast enhancement technique.
| -opaque <color>
| change this color to the pen color within the image
| The color is specified using the format described in the "Color Names" section of X(1).
| See -fill for more details.
| -page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
| size and location of an image canvas
| Use this option to specify the dimensions of the PostScript page in dots per inch or a TEXT page in pixels. The choices for a PostScript page are:
         11x17         792  1224
         Ledger       1224   792
         Legal         612  1008
         Letter        612   792
         LetterSmall   612   792
         ArchE        2592  3456
         ArchD        1728  2592
         ArchC        1296  1728
         ArchB         864  1296
         ArchA         648   864
         A0           2380  3368
         A1           1684  2380
         A2           1190  1684
         A3            842  1190
         A4            595   842
         A4Small       595   842
         A5            421   595
         A6            297   421
         A7            210   297
         A8            148   210
         A9            105   148
         A10            74   105
         B0           2836  4008
         B1           2004  2836
         B2           1418  2004
         B3           1002  1418
         B4            709  1002
         B5            501   709
         C0           2600  3677
         C1           1837  2600
         C2           1298  1837
         C3            918  1298
         C4            649   918
         C5            459   649
         C6            323   459
         Flsa          612   936
         Flse          612   936
         HalfLetter    396   612
| For convenience you can specify the page size by media (e.g. A4, Ledger, etc.). Otherwise, -page behaves much like -geometry (e.g. `-page letter+43+43>`).
| This option is also used to place subimages when writing to a multi-image format that supports offsets, such as GIF89 and MNG. When used for this purpose the offsets are always measured from the top left corner of the canvas and are not affected by the -gravity option. To position a GIF or MNG image, use -page{+-}<x>{+-}<y> (e.g. -page +100+200). When writing to a MNG file, a -page option appearing ahead of the first image in the sequence with nonzero width and height defines the width and height values that are written in the MHDR chunk. Otherwise, the MNG width and height are computed from the bounding box that contains all images in the sequence. When writing a GIF89 file, only the bounding box method is used to determine its dimensions.
| For a PostScript page, the image is sized as in -geometry and positioned relative to the lower left hand corner of the page by {+-}<x offset>{+-}<y offset>. Use `-page 612x792>`, for example, to center the image within the page. If the image size exceeds the PostScript page, it is reduced to fit the page. The default gravity for the -page option is NorthWest, i.e., positive x and y offset are measured rightward and downward from the top left corner of the page, unless the -gravity option is present with a value other than NorthWest.
| The default page dimensions for a TEXT image is 612x792.
| This option is used in concert with -density.
| -paint <radius>
| simulate an oil painting
| Each pixel is replaced by the most frequent color in a circular neighborhood whose width is specified with radius.
| -pause <seconds>
| pause between animation loops [animate]
| Pause for the specified number of seconds before repeating the animation.
| -pause <seconds>
| pause between snapshots [import]
| Pause for the specified number of seconds before taking the next snapshot.
| -pen <color>
| specify the pen color for drawing operations
| The color is specified using the format described in the "Color Names" section of X(1).
| This option is deprecated; use -fill instead.
| -ping
| efficiently determine image characteristics
| -pointsize <value>
| pointsize of the PostScript, OPTION1, or TrueType font
| -preview <type>
| image preview type
| Use this option to affect the preview operation of an image (e.g. `convert -preview Gamma Preview:gamma.png`). Choose from these previews:
         Rotate
         Shear
         Roll
         Hue
         Saturation
         Brightness
         Gamma
         Spiff
         Dull
         Grayscale
         Quantize
         Despeckle
         ReduceNoise
         Add Noise
         Sharpen
         Blur
         Threshold
         EdgeDetect
         Spread
         Shade
         Raise
         Segment
         Solarize
         Swirl
         Implode
         Wave
         OilPaint
         CharcoalDrawing
         JPEG
| The default preview is JPEG.
| -process <command>
| process a sequence of images
| The sequence of images is terminated by the appearance of any option.
| If the -process option appears after all of the input images, all images are processed.
| -profile <filename>
| add ICM, IPTC, or generic profile to image
| `-profile filename` adds an ICM (ICC color management), IPTC (newswire information), or a generic profile to the image
.
| Use `+profile icm`, `+profile iptc`, or `+profile profile_name` to remove the respective profile. Use `identify -verbose` to find out what profiles are in the image file. Use `+profile "*"` to remove all profiles.
| To extract a profile, the -profile option is not used. Instead, simply write the file to an image format such as APP1, 8BIM, ICM, or IPTC.
| For example, to extract the Exif data (which is stored in JPEG files in the APP1 profile), use
        gm convert cockatoo.jpg exifdata.app1
| -quality <value>
| JPEG/MIFF/PNG compression level
| For the JPEG and MPEG image formats, quality is 0 (lowest image quality and highest compression) to 100 (best quality but least effective compression). The default quality is 75. Use the -sampling-factor option to specify the factors for chroma downsampling.
| For the MIFF image format, quality/10 is the zlib compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.
| For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). Compression levels range from 0 (fastest compression) to 100 (best but slowest). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression.
| If filter-type is 4 or less, the specified filter-type is used for all scanlines:
         0: none
         1: sub
         2: up
         3: average
         4: Paeth
| If filter-type is 5, adaptive filtering is used when quality is greater than 50 and the image does not have a color map, otherwise no filtering is used.
| If filter-type is 6, adaptive filtering with minimum-sum-of-absolute-values is used.
| Only if the output is MNG, if filter-type is 7, the LOCO color transformation and adaptive filtering with minimum-sum-of-absolute-values are used.
| The default is quality is 75, which means nearly the best compression with adaptive filtering. The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.
| For further information, see the PNG specification.
| -raise <width>x<height>
| lighten or darken image edges
| This will create a 3-D effect. See -geometry for details details about the geometry specification. Offsets are not used.
| Use -raise to create a raised effect, otherwise use +raise.
| -red-primary <x>,<y>
| red chromaticity primary point
| -region <width>x<height>{+-}<x>{+-}<y>
| apply options to a portion of the image
| The x and y offsets are treated in the same manner as in -crop
.
| -remote
| perform a remote operation
| The only command recognized at this time is the name of an image file to load.
| -resize <width>x<height>{%}{@}{!}{<}{>}
| resize an image
| This is an alias for the -geometry option and it behaves in the same manner. If the -filter option precedes the -resize option, the specified filter is used.
| There are some exceptions:
| When used as a composite option, -resize conveys the preferred size of the output image, while -geometry conveys the size and placement of the composite image within the main image.
| When used as a montage option, -resize conveys the preferred size of the montage, while -geometry conveys information about the tiles.
| -roll {+-}<x>{+-}<y>
| roll an image vertically or horizontally
| See -geometry for details the geometry specification. The x and y offsets are not affected by the -gravity option.
| A negative x offset rolls the image left-to-right. A negative y offset rolls the image top-to-bottom.
| -rotate <degrees>{<}{>}
| apply Paeth image rotation to the image
| Use `>` to rotate the image only if its width exceeds the height. `<` rotates the image only if its width is less than the height. For example, if you specify `-rotate "-90>"` and the image size is 480x640, the image is not rotated. However, if the image is 640x480, it is rotated by -90 degrees. If you use `>` or `<`, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.
| Empty triangles left over from rotating the image are filled with the color defined as background (class backgroundColor). See X(1) for details.
| -sample <geometry>
| scale image with pixel sampling
| See -geometry for details about the geometry specification. -sample ignores the -filter selection if the -filter option is present. Offsets, if present in the geometry string, are ignored, and the -gravity option has no effect.
| -sampling-factor <horizontal_factor>x<vertical_factor>
| sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.
| This option specifies the sampling factors to be used by the JPEG encoder for chroma downsampling. If this option is omitted, the JPEG library will use its own default values. When reading or writing the YUV format and when writing the M2V (MPEG-2) format, use -sampling-factor 2x1 to specify the 4:2:2 downsampling method.
| -scale <geometry>
| scale the image.
| See -geometry for details about the geometry specification. -scale uses a simpler, faster algorithm, and it ignores the -filter selection if the -filter option is present. Offsets, if present in the geometry string, are ignored, and the -gravity option has no effect.
| -scene <value>
| set scene number
| This option sets the scene number of an image or the first image in an image sequence.
| -scenes <value-value>
| range of image scene numbers to read
| Each image in the range is read with the filename followed by a period (.) and the decimal scene number. You can change this behavior by embedding a %d, %0Nd, %o, %0No, %x, or %0Nx printf format specification in the file name. For example,
        gm montage -scenes 5-7 image.miff
| makes a montage of files image.miff.5, image.miff.6, and image.miff.7, and
        gm animate -scenes 0-12 image%02d.miff
| animates files image00.miff, image01.miff, through image12.miff.
| -screen
| specify the screen to capture
| This option indicates that the GetImage request used to obtain the image should be done on the root window, rather than directly on the specified window. In this way, you can obtain pieces of other windows that overlap the specified window, and more importantly, you can capture menus or other popups that are independent windows but appear over the specified window.
| -seed <value>
| pseudo-random number generator seed value
| -segment <cluster threshold>x<smoothing threshold>
| segment an image
| Segment an image by analyzing the histograms of the color components and identifying units that are homogeneous with the fuzzy c-means technique.
| Specify cluster threshold as the number of pixels in each cluster must exceed the the cluster threshold to be considered valid. Smoothing threshold eliminates noise in the second derivative of the histogram. As the value is increased, you can expect a smoother second derivative. The default is 1.5. See "Image Segmentation" for details.
| -shade <azimuth>x<elevation>
| shade the image using a distant light source
| Specify azimuth and elevation as the position of the light source. Use +shade to return the shading results as a grayscale image.
| -shadow <radius>x<sigma>
| shadow the montage
| -shared-memory
| use shared memory
| This option specifies whether the utility should attempt use shared memory for pixmaps. GraphicsMagick must be compiled with shared memory support, and the display must support the MIT-SHM extension. Otherwise, this option is ignored. The default is True.
| -sharpen <radius>x<sigma>
| sharpen the image
| Use a Gaussian operator of the given radius and standard deviation (sigma).
| -shave <width>x<height>
| shave pixels from the image edges
| Specify the width of the region to be removed from both sides of the image and the height of the regions to be removed from top and bottom.
| -shear <x degrees>x<y degrees>
| shear the image along the X or Y axis
| Use the specified positive or negative shear angle.
| Shearing slides one edge of an image along the X or Y axis, creating a parallelogram. An X direction shear slides an edge along the X axis, while a Y direction shear slides an edge along the Y axis. The amount of the shear is controlled by a shear angle. For X direction shears, x degrees is measured relative to the Y axis, and similarly, for Y direction shears y degrees is measured relative to the X axis.
| Empty triangles left over from shearing the image are filled with the color defined as background (class backgroundColor). See X(1) for details.
| -silent
| operate silently
| -size <width>x<height>{+offset}
| width and height of the image
| Use this option to specify the width and height of raw images whose dimensions are unknown such as GRAY, RGB, or CMYK. In addition to width and height, use -size with an offset to skip any header information in the image or tell the number of colors in a MAP image file, (e.g. -size 640x512+256).
| For Photo CD images, choose from these sizes:
         192x128
         384x256
         768x512
         1536x1024
         3072x2048
| Finally, use this option to choose a particular resolution layer of a JBIG or JPEG image (e.g. -size 1024x768).
| -snaps <value>
| number of screen snapshots
| Use this option to grab more than one image from the X server screen, to create an animation sequence.
| -solarize <factor>
| negate all pixels above the threshold level
| Specify factor as the percent threshold of the intensity (0 - 99.9%).
| This option produces a solarization effect seen when exposing a photographic film to light during the development process.
| -spread <amount>
| displace image pixels by a random amount
| Amount defines the size of the neighborhood around each pixel to choose a candidate pixel to swap.
| -stegano <offset>
| hide watermark within an image
| Use an offset to start the image hiding some number of pixels from the beginning of the image. Note this offset and the image size. You will need this information to recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).
| -stereo
| composite two images to create a stereo anaglyph
| The left side of the stereo pair is saved as the red channel of the output image. The right side is saved as the green channel. Red-green stereo glasses are required to properly view the stereo image.
| -stroke <color>
| color to use when stroking a graphic primitive
| The color is specified using the format described in the "Color Names" section of X(1).
| See -draw for further details.
| -strokewidth <value>
| set the stroke width
| See -draw for further details.
| -swirl <degrees>
| swirl image pixels about the center
| Degrees defines the tightness of the swirl.
| -text-font <name>
| font for writing fixed-width text
| Specifies the name of the preferred font to use in fixed (typewriter style) formatted text. The default is 14 point Courier.
| You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example, `Courier.ttf` is a TrueType font and `x:fixed` is OPTION1.
| -texture <filename>
| name of texture to tile onto the image background
| -threshold <value>{%}
| threshold the image
| Create a bi-level image such that any pixel intensity that is equal or exceeds the threshold is reassigned the maximum intensity otherwise the minimum intensity.
| -tile <filename>
| tile image when filling a graphic primitive
| -tile <geometry>
| layout of images [montage]
| -title <string>
| assign title to displayed image [animate, display, montage]
| Use this option to assign a specific title to the image. This is assigned to the image window and is typically displayed in the window title bar. Optionally you can include the image filename, type, width, height, Exif data, or other image attribute by embedding special format characters described under the -format option.
| For example,
         -title "%m:%f %wx%h"
| produces an image title of `MIFF:bird.miff 512x480` for an image titled `bird.miff` and whose width is 512 and height is 480.
| -transform
| transform the image
| This option applies the transformation matrix from a previous -affine option.
        gm convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
| -transparent <color>
| make this color transparent within the image
| The color is specified using the format described in the "Color Names" section of X(1).
| -treedepth <value>
| tree depth for the color reduction algorithm
| Normally, this integer value is zero or one. A zero or one tells display to choose an optimal tree depth for the color reduction algorithm
| An optimal depth generally allows the best representation of the source image with the fastest computational speed and the least amount of memory. However, the default depth is inappropriate for some images. To assure the best representation, try values between 2 and 8 for this parameter. Refer to quantize for more details.
| The -colors or -monochrome option is required for this option to take effect.
| -trim
| trim an image
| This option removes any edges that are exactly the same color as the corner pixels. Use -fuzz to make -trim remove edges that are nearly the same color as the corner pixels.
| -type <type>
| the image type
| Choose from: Bilevel, Grayscale, Palette, PaletteMatte, TrueColor, TrueColorMatte, ColorSeparation, ColorSeparationMatte, or Optimize.
| Normally, when a format supports different subformats such as grayscale and truecolor, the encoder will try to choose an efficient subformat. The -type option can be used to overrride this behavior. For example, to prevent a JPEG from being written in grayscale format even though only gray pixels are present, use
        gm convert bird.pgm -type TrueColor bird.jpg
| Similarly, using `-type TrueColorMatte` will force the encoder to write an alpha channel even though the image is opaque, if the output format supports transparency.
| -update <seconds>
| detect when image file is modified and redisplay.
| Suppose that while you are displaying an image the file that is currently displayed is over-written. display will automatically detect that the input file has been changed and update the displayed image accordingly.
| -units <type>
| the type of image resolution
| Choose from: Undefined, PixelsPerInch, or PixelsPerCentimeter.
| -unsharp <radius>x<sigma>+<amount>+<threshold>
| sharpen the image with an unsharp mask operator
| The -unsharp option sharpens an image. We convolve the image with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.
| The parameters are:
        radius:    The radius of the Gaussian, in pixels,  not
                   counting the center pixel (default 0).
        sigma:     The standard deviation of the Gaussian, in
                   pixels (default 1.0).
        amount:    The percentage of the difference between the
                   original and the blur image that is added back
                   into the original (default 1.0).
        threshold: The threshold, as a fraction of MaxRGB, needed
                   to apply the difference amount (default 0.05).
| -use-pixmap
| use the pixmap
| -verbose
| print detailed information about the image
| This information is printed: image scene number; image name; image size; the image class (DirectClass or PseudoClass); the total number of unique colors; and the number of seconds to read and transform the image. Refer to miff for a description of the image class.
| If -colors is also specified, the total unique colors in the image and color reduction error values are printed. Refer to quantize for a description of these values.
| -version
| print GraphicsMagick version string
| -view <string>
| FlashPix viewing parameters
| -virtual-pixel <method>
| specify contents of "virtual pixels"
| This option defines "virtual pixels" for use in operations that can access pixels outside the boundaries of an image.
| Choose from these methods:
        Constant:  Use the image background color.
        Edge:      Extend the edge pixel toward infinity (default).
        Mirror:    Mirror the image.
        Tile:      Tile the image.
| This option affects operations that use virtual pixels such as -blur, -sharpen, -wave, etc.
| -visual <type>
| animate images using this X visual type
| Choose from these visual classes:
         StaticGray
         GrayScale
         StaticColor
         PseudoColor
         TrueColor
         DirectColor
         default
         visual id
| The X server must support the visual you choose, otherwise an error occurs. If a visual is not specified, the visual class that can display the most simultaneous colors on the default screen is chosen.
| -watermark <brightness>x<saturation>
| percent brightness and saturation of a watermark
| -wave <amplitude>x<wavelength>
| alter an image along a sine wave
| Specify amplitude and wavelength of the wave.
| -white-point <x>,<y>
| chromaticity white point
| -window <id>
| make image the background of a window
| id can be a window id or name. Specify root to select X's root window as the target window.
| By default the image is tiled onto the background of the target window. If backdrop or -geometry are specified, the image is surrounded by the background color. Refer to X RESOURCES for details.
| The image will not display on the root window if the image has more unique colors than the target window colormap allows. Use -colors to reduce the number of colors.
| -window-group
| specify the window group
| -write <filename>
| write an image sequence [convert, composite]
| The image sequence following the -write filenameoption is written out, and then processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the +write filename option.
| -write <filename>
| write the image to a file [display]
| If filename already exists, you will be prompted as to whether it should be overwritten.
| By default, the image is written in the format that it was read in as. To specify a particular image format, prefix filename with the image type and a colon (e.g., ps:image) or specify the image type as the filename suffix (e.g., image.ps). See convert(1) for a list of valid image formats. Specify file as - for standard output. If file has the extension .Z or .gz, the file size is compressed using compress or gzip respectively. Precede the image file name with | to pipe to a system command.
| Use -compress to specify the type of image compression.
| The equivalent X resource for this option is writeFilename (class WriteFilename). See X Resources for details.

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Environment

| DISPLAY
| To get the default host, display number, and screen.

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Authors

| John Cristy, magick-users@graphicsmagick.org, GraphicsMagick Group, Glenn Randers-Pehrson, randeg@alum.rpi.edu, GraphicsMagick Group.

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Copyright

| Copyright (C) 2002 GraphicsMagick Group Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files ("GraphicsMagick"), to deal in GraphicsMagick without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of GraphicsMagick, and to permit persons to whom the GraphicsMagick is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of GraphicsMagick. The software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement.In no event shall GraphicsMagick Group be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with GraphicsMagick or the use or other dealings in GraphicsMagick. Except as contained in this notice, the name of the GraphicsMagick Group shall not be used in advertising or otherwise to promote the sale, use or other dealings in GraphicsMagick without prior written authorization from the GraphicsMagick Group.

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Image manipulation software that works like magic.