phpthumb_functions::GetPixelColor PHP Method

    public static function GetPixelColor(&$img, $x, $y)
    {
        if (!is_resource($img)) {
            return false;
        }
        return @ImageColorsForIndex($img, @ImageColorAt($img, $x, $y));
    }

 function GD2BMPstring(&$gd_image)
 {
     $imageX = ImageSX($gd_image);
     $imageY = ImageSY($gd_image);
     $BMP = '';
     for ($y = $imageY - 1; $y >= 0; $y--) {
         $thisline = '';
         for ($x = 0; $x < $imageX; $x++) {
             $argb = phpthumb_functions::GetPixelColor($gd_image, $x, $y);
             $thisline .= chr($argb['blue']) . chr($argb['green']) . chr($argb['red']);
         }
         while (strlen($thisline) % 4) {
             $thisline .= "";
         }
         $BMP .= $thisline;
     }
     $bmpSize = strlen($BMP) + 14 + 40;
     // BITMAPFILEHEADER [14 bytes] - http://msdn.microsoft.com/library/en-us/gdi/bitmaps_62uq.asp
     $BITMAPFILEHEADER = 'BM';
     // WORD    bfType;
     $BITMAPFILEHEADER .= phpthumb_functions::LittleEndian2String($bmpSize, 4);
     // DWORD   bfSize;
     $BITMAPFILEHEADER .= phpthumb_functions::LittleEndian2String(0, 2);
     // WORD    bfReserved1;
     $BITMAPFILEHEADER .= phpthumb_functions::LittleEndian2String(0, 2);
     // WORD    bfReserved2;
     $BITMAPFILEHEADER .= phpthumb_functions::LittleEndian2String(54, 4);
     // DWORD   bfOffBits;
     // BITMAPINFOHEADER - [40 bytes] http://msdn.microsoft.com/library/en-us/gdi/bitmaps_1rw2.asp
     $BITMAPINFOHEADER = phpthumb_functions::LittleEndian2String(40, 4);
     // DWORD  biSize;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String($imageX, 4);
     // LONG   biWidth;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String($imageY, 4);
     // LONG   biHeight;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(1, 2);
     // WORD   biPlanes;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(24, 2);
     // WORD   biBitCount;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(0, 4);
     // DWORD  biCompression;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(0, 4);
     // DWORD  biSizeImage;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(2835, 4);
     // LONG   biXPelsPerMeter;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(2835, 4);
     // LONG   biYPelsPerMeter;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(0, 4);
     // DWORD  biClrUsed;
     $BITMAPINFOHEADER .= phpthumb_functions::LittleEndian2String(0, 4);
     // DWORD  biClrImportant;
     return $BITMAPFILEHEADER . $BITMAPINFOHEADER . $BMP;
 }