Как сделать водяной знак в каталоге?

<?
 
waterMark($_SERVER['DOCUMENT_ROOT'].$_SERVER['REQUEST_URI'], "_watermark.png", "bottom=5,right=5");
 
function waterMark($original, $watermark, $placement = 'bottom=5,right=5', $destination = null) {
   $info_o = @getImageSize($original);
   if (!$info_o)
         return false;
   $info_w = @getImageSize($watermark);
   if (!$info_w)
         return false;
 
   list ($vertical, $horizontal) = split(',', $placement,2);
   list($vertical, $sy) = split('=', trim($vertical),2);
   list($horizontal, $sx) = split('=', trim($horizontal),2);
 
   switch (trim($vertical)) {
      case 'bottom':
         $y = $info_o[1] - $info_w[1] - (int)$sy;
         break;
      case 'middle':
         $y = ceil($info_o[1]/2) - ceil($info_w[1]/2) + (int)$sy;
         break;
      default:
         $y = (int)$sy;
         break;
      }
 
   switch (trim($horizontal)) {
      case 'right':
         $x = $info_o[0] - $info_w[0] - (int)$sx;
         break;
      case 'center':
         $x = ceil($info_o[0]/2) - ceil($info_w[0]/2) + (int)$sx;
         break;
      default:
         $x = (int)$sx;
         break;
      }
 
   header("Content-Type: ".$info_o['mime']);
 
   $original = @imageCreateFromString(file_get_contents($original));
   $watermark = @imageCreateFromString(file_get_contents($watermark));
   $out = imageCreateTrueColor($info_o[0],$info_o[1]);
 
   imageCopy($out, $original, 0, 0, 0, 0, $info_o[0], $info_o[1]);
   imageCopy($out, $watermark, $x, $y, 0, 0, $info_w[0], $info_w[1]);
 
   switch ($info_o[2]) {
      case 1:
         imageGIF($out);
         break;
      case 2:
         imageJPEG($out);
         break;
      case 3:
         imagePNG($out);
         break;
         }
 
   imageDestroy($out);
   imageDestroy($original);
   imageDestroy($watermark);
 
   return true;
   }
 
?> 

Options +Indexes
DirectoryIndex index.htm
 
<FilesMatch "\.(gif|jpg|png)$">
   RewriteEngine On
   RewriteCond %{REQUEST_FILENAME} -f
   RewriteRule ^(.*)$ /watermark/_watermark.php [T=application/x-httpd-php,L,QSA]
</FilesMatch>