Convert an image into digits with PHP? -

i trying figure out how can convert color image numbers.

for example, if have image 1 shown in figure (b), how can output figure (a) in text file?

i took in here mehdi karamosly mentioned in answer , modified little bit simipiler , made simple html output can modify outputs liking. might want add more data checking make sure file/real image if looking add security. i've checked out on computer , works , work need modification(s).

function graycolor($img){     list($width, $height) = getimagesize($img);     $mime = pathinfo($img, pathinfo_extension);     switch($mime){#use appropriate function depending on image type         case 'jpg':         case 'jpeg':             $im = imagecreatefromjpeg($img);             break;         case 'png':             $im = imagecreatefrompng($img);             break;         case 'gif':             $im = imagecreatefromgif($img);             break;         default:             #invalid type             exit;     }     if(!is_color($img, $im)){#$img = string; $im = resource string         $ret = "";         for($i = 0; $i < $height; $i++){#loop height pixels             for($ii = 0; $ii < $width; $ii++){#loop width pixels                 $color = imagecolorat($im, $ii, $i);                 $color = imagecolorsforindex($im, $color);                 $ret .= $color['red'] . " ";             }                 $ret .= "\n";         }         return $ret;     }else{         #$ret = "";         #for($i = 0; $i < $height; $i++){#loop height pixels             #for($ii = 0; $ii < $width; $ii++){#loop width pixels                 #$color = imagecolorat($im, $ii, $i);                 #$color = imagecolorsforindex($im, $color);                 #$ret .= $color['red'] . ", " . $color['green'] . ", " . $color['blue'] . " ";             #}                 #$ret .= "\n";         #}         return "color image";     }  } function is_color($img, $im){     $times = 10;#number of times check image color     $iscolor = false;     list($width, $height) = getimagesize($img);     for($i = 0 ; $i < $times && !$iscolor; $i++){         $color = imagecolorat($im, rand(0, $width), rand(0, $height));#get random cords         $color = imagecolorsforindex($im, $color);#get random color's values         if($color['red'] !== $color['green'] || $color['green'] !== $color['blue']){             $iscolor = true;             break;         }     }     return $iscolor; }  echo graycolor('color.jpg');#outputs color image echo graycolor('gray.jpg');#outputs numbers