PHP - watermarking images

watermark_image.php

<?php

function watermark_image($target, $wtrmrk_file, $newcopy) 
{
      // Load the stamp and the photo to apply the watermark to
      $stamp = imagecreatefrompng($wtrmrk_file);
      $im = imagecreatefromjpeg($target);
      // Set the margins for the stamp and get the height/width of the stamp image
      $marge_right = 10;
      $marge_bottom = 10;
      $sx = imagesx($stamp);
      $sy = imagesy($stamp);
      // Copy the stamp image onto our photo using the margin offsets and the photo
      // width to calculate positioning of the stamp.
      imagecopy($im, $stamp, imagesx($im) - $sx - $marge_right, imagesy($im) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp));
      imagejpeg($im, $newcopy, 100);
      // Output and free memory
      imagedestroy($im);
      return $newcopy;
  }