This script creates a watermarked image from an image file (.jpg .gif or .png). The watermark must be a transparent gif or png image. Save the script into watermark.php.

The process of creating the image are:

• Create the image and the watermark image using @imagecreatefromgif, @imagecreatefrompng, or @imagecreatefromjpeg.
• Use the imagecopy to copy part of an image to another image.

You can download the full script here.