<?php
$imagesource = $_GET['path'];
$filetype = substr($imagesource,strlen($imagesource)-4,4);
$filetype = strtolower($filetype);
if($filetype == ".gif") $image = @imagecreatefromgif($imagesource);
if($filetype == ".jpg") $image = @imagecreatefromjpeg($imagesource);
if($filetype == ".png") $image = @imagecreatefrompng($imagesource);
if (!$image) die();
header('Content-Type: image/png');
$watermark = @imagecreatefrompng('watermark.png');
$imagewidth = imagesx($image);
$imageheight = imagesy($image);.
$watermarkwidth = imagesx($watermark);
$watermarkheight = imagesy($watermark);
$startwidth = (($imagewidth - $watermarkwidth)/2);
$startheight = (($imageheight - $watermarkheight)/2);
imagecopy($image, $watermark, $startwidth, $startheight, 0, 0, $watermarkwidth, $watermarkheight);
imagejpeg($image);
imagedestroy($image);
imagedestroy($watermark);
?>