Couleur d une partie d une image php

$filename="./tmp.jpg";
$image_p = imagecreatefromjpeg($filename);
list($width_orig, $height_orig) = getimagesize($filename);
$im =imagecreatetruecolor($lg, $ht);
     imagecopy ( $im , $image_p , 0 , 0 , $width_orig-$lg, $height_orig-$ht , $lg, $ht);
     imagejpeg($im,$Directory."/tmp".$i."-couleur.jpg" );
     $colors = array(
             array(203, 203, 203),     //like white
             array(153, 153, 153),    //like grey
             array(103, 103, 103),   //like more grey
             array(53, 53, 53));    //like black
             echo"<br>";
     foreach($colors as $id => $rgb)
     {
      $result = imagecolorclosesthwb($im, $rgb[0], $rgb[1], $rgb[2]);
      $color2="#".dechex($result).dechex($result).dechex($result);
      $color1="#".dechex($rgb[0]).dechex($rgb[1]).dechex($rgb[2]);
      echo "#$id:<font color="$color1"> Recherche </font> ($rgb[0], $rgb[1], $rgb[2]); <font color="$color2">Correspondance </font>: $result.<br>\n";
}