Image Manipulator is a PHP class with the purpose to manipulate images in different ways. Using the GD Image Library, it can manipulate all of the major image formats and maintain transparency for png and gif images.
Features
Smart resizing
Watermarking
Grayscaling
Cropping
Stacking methods
Outputting on the fly
Modify quality
Take a look at the live preview for a demonstration and instructions on how to use all of the features.