DELPHI AREA Forum

Hi. I am looking for a faster way than scanline to access image data. I know it is possible to do so by using pointer operation. For example I need to get a pointer to the fisrt pixel of the image. To do so, I use scanline , but I have some difficulties with it, for instance I tried the following code:

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 var PixelPointer,StartPointer:PByte
     b:byte;

 Bmp.Width:=640;
 Bmp.Height:=640;
 Bmp.PixelFormat:=pf24bit;// Pixel order: RGB RGB RGB ....

 StartPointer:=Bmp.ScanLine[0];
 PixelPointer := pointer(integer(StartPointer)+10*width+5);//pixel[5,10]
 Move(PixelPointer^, b, 1);  <<EAccessViolation!!!


But it raised an EAccessViolation exception. Do you know what is the problem? I want to get the RGB value of each pixel inside the image. Anyway, do you know any other way for obtaining the pointer to the image data? Thanks

Bits of some bitmaps are arranged upside down. In this case, the first pixel is the bottom-left pixel.

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FirstPixel := Bitamp.ScanLine[Bitmap.Height - 1];