Dette er et lite knippe Delphi triks lagret online mest for min egen del, men Google er snille mot oss.

ImageMagick, for fancy billedbehandlig.

ImageMagick for Delphi & varianter ligger her:
http://sourceforge.net/project/showfiles.php?group_id=92177&package_id=174103&release_id=431432

Se også:
http://wiki.lazarus.freepascal.org/PascalMagick

Alle API kall ligger beskrevet her:
http://imagemagick.org/script/magick-wand.php

  • Lage et bilde:
    • uses
  DFCreatorPilot3Lib_TLB, Magick_wand, ImageMagick;

procedure ThrowWandException(wand: PMagickWand);
var
  description : PChar;
  severity : ExceptionType;
begin
  description:= MagickGetException(wand, @severity);
  MessageBox(Form1.Handle, PChar(Format('An error ocurred. Description: %s', [description])), 'ImageMagick', 0);
  MagickRelinquishMemory(description);
end;

var
  wand : PMagickWand;
  pixelwand : PPixelWand;
  status : MagickBooleanType;
begin
  MagickWandGenesis;

  // Some bugs here...

  wand:= NewMagickWand;
  pixelwand:= NewPixelWand;
  PixelSetColor(pixelwand, 'white');

  status:= MagickNewImage(wand, newwidth, newheight, pixelwand);
  if status = MagickFalse then
    ThrowWandException(wand);

  DestroyPixelWand(pixelwand);

  // Even more bugs here...

  MagickWandTerminus;
end;
  • Lese et bilde fra fil:
    • begin
  status:= MagickReadImage(wand, 'bilde.jpg');
  if status = MagickFalse then
    ThrowWandException(wand);
end;
  • Sette et bilde (tempwand) inn i et annet (wand):
    • begin
  status:= MagickCompositeImage(wand, tempwand, AtopCompositeOp, x-pos, y-pos);
  if status = MagickFalse then
    ThrowWandException(wand);
end;
  • Ta et utsnitt av et bilde:
    • begin
  status:= MagickCropImage(wand, width, height, x-pos, y-pos);
  if status = MagickFalse then
    ThrowWandException(wand);
end;
  • Fjerne alt 'hvitt' rundt et bilde:
    • begin
  status:= MagickTrimImage(wand, 0);
  if status = MagickFalse then
    ThrowWandException(wand);
end;
  • Endre størrelse på et bilde:
    • begin
  status:= MagickScaleImage(wand, new-width, new-height);
  if status = MagickFalse then
    ThrowWandException(wand);

// Andre muligheter:
//  status:= MagickResizeImage(wand, new-width, new-height, LanczosFilter, 0);
//  status:= MagickSampleImage(wand, new-width, new-height);

end;
  • Frigjøre et bilde fra minne:
    • begin
 if IsMagickWand(wand) = MagickTrue then
   DestroyMagickWand(wand);
end;
  • Bruke ImageMagick og PDF Creator Pilot sammen via minne:

    • http://www.colorpilot.com/pdflibrary.html 

    var
  wand : PMagickWand;
  status : MagickBooleanType;
  PDF : TPDFDocument3; // Not tested on TPDFDocument4, should be the same...
  t : integer;
  b : pointer;
  l : cardinal;
begin
  status:= MagickSetImageFormat(wand, 'png');
  if status = MagickFalse then
    ThrowWandException(wand);

  status:= MagickSetImageCompression(wand, NoCompression);
  if status = MagickFalse then
    ThrowWandException(wand);

// Må legges til i magick_image.inc:
// function MagickWriteImageBlob(wand: PMagickWand; var length: Cardinal): Pointer; cdecl; external WandExport;

  b:= MagickWriteImageBlob(wand, l);
  t:= PDF.AddImageFromMemory(b, l, itcJpeg);
  MagickRelinquishMemory(b);

  if t = -1 then
    'Handle some PDF Creator Error!'
  else
    PDF.PDFPAGE_ShowImage(t, x-pos, y-pos, width, height, 0);
end;
  • Ta en kopi av et bilde:
    • begin
//  cropwand:= NewMagickWand;
  cropwand:= CloneMagickWand(wand);
  if status = MagickFalse then
    ThrowWandException(cropwand);
end;
  • Lagre et bilde:
    • begin
  status:= MagickSetImageCompressionQuality(wand, 50);
  if status = MagickFalse then
    ThrowWandException(wand);

  status:= MagickWriteImage(wand, PChar('nyttbilde.jpg'));
  if status = MagickFalse then
    ThrowWandException(wand);
end;