TImage manipulatione
lazarus / 39-Graphics

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xinyiman · 2016-07-28 09:52

hello guys, a question. There is a native library lazarus or who is
cross-platform and has no external dependencies for manipulating
picture contained in a TImage? I mainly serve

rotation
contrast
brightness
zoom


thank you

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Sanem · 2016-07-28 13:08

Did you test BGRABitmap? You can edit the bitmap and then assign it
into the TImage.

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xinyiman · 2016-07-28 13:20

No, you have some examples to the functions I mentioned above?

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lainz · 2016-07-28 15:55

BGRABitmap Rotate:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  
Bitmap.RotateCCW;  Bitmap.RotateCW;  VerticalFlip(ARect: TRect); 
HorizontalFlip(ARect: TRect); 
Zoom:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Resample(newWidth, newHeight: integer;      mode: TResampleMode =
rmFineResample): TBGRACustomBitmap;
You can access the pixels this way to apply any filter you want:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i // all
pixels //var  i: integer;  p: PBGRAPixel;begin  p := Bitmap.Data;  
for i := Bitmap.NBPixels-1 downto 0 do  begin    p^.red := ;   
p^.green := ;    p^.blue := ;    p^.alpha := ;    Inc(p);  end;
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i // scan
line //var  x, y: integer;  p: PBGRAPixel;begin  for y := 0 to
Bitmap.Height - 1 do  begin    p := Bitmap.Scanline[y];    for x := 0
to Bitmap.Width - 1 do    begin      p^.red := ;      p^.green := ;  
  p^.blue := ;      p^.alpha := ;      Inc(p);    end;  end; 
Bitmap.InvalidateBitmap;

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xinyiman · 2016-07-28 16:25

But BGRABitmap run on Mac OSX?!

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lainz · 2016-07-28 17:01

Quote from: xinyiman on July 28, 2016, 06:25:36 pmBut BGRABitmap run
on Mac OSX?!

Yes

Quote                                bgrabitmap.pas
                                --------------
                 Free easy-to-use memory bitmap 32-bit,
                 8-bit for each channel, transparency.
                 Channels can be in the following orders:
                 - B G R A (recommended for Windows, required for
fpGUI)
                 - R G B A (recommended for Gtk and MacOS)

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xinyiman · 2016-07-28 20:43

Ok, it works on window. Then in the next few days I try on linux and
mac. Now I wanted to understand how to manage the brightness and
contrast of the image.

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xinyiman · 2016-07-28 20:56

on linux I have the following problem when you compile the source.
Why? How do you solve?

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i function
TBGRASVG.GetViewBox(AUnit: TCSSUnit): TSVGViewBox;begin  with ViewBox
do  begin    result.min := FUnits.ConvertCoord(min,cuCustom,AUnit);  
result.size := FUnits.ConvertCoord(size,cuCustom,AUnit);  end;end; 
Messaggi, avvertimenti: 1
Warning: other unit files search path (aka unit path) of "project1"
contains "/home/francesco/Documenti/Lazarus_Componenti/bgrabitmap9.1",
which belongs to package "BGRABitmapPack"
Compile package BGRABitmapPack 9.1: Codice di uscita 256, Errori: 1
bgrasvg.pas(346,8) Error: Internal error 2012090607

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lainz · 2016-07-28 21:39

I dont know. Try reporting it in the bgrabitmap subforum.

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circular · 2016-07-29 14:13

Continued there:
http://forum.lazarus.freepascal.org/index.php/topic,33523.0.html