PHP - GD Watermarker: Apply an watermark image on another image

This class can be used to apply an watermark image on another image.

It can load an image in PNG or JPEG format and can place a transparent watermark image over the original image.

The watermark image horizontal and vertical alignment and border padding are configurable parameters.

The resulting image with the applied watermark image is saved to a file with the same name of the original, but the class generates a backup copy before applying the watermark image.