GDI+压缩图片 image/png image/jpeg

var
  encoderClsid: TGUID;
  stat: TStatus;
  image: TGPImage;
begin
  image := TGPImage.Create('a.bmp');
  GetEncoderClsid('image/jpeg', encoderClsid);
  stat := image.save('a.jpg', encoderClsid, nil);
  if ( stat= OK ) then
    memo1.lines.add('Save Successfully!')
  else 
    memo1.lines.add( format( 'Failure: stat = %s',[GetStatus(stat)]));
  image.free;
end;