Crop Canvas
This is a class allows you to crop an image in a variety of ways. You can crop in an absolute or relative way (to a certain size or by a certain size), both as a pixel number or a percentage. You can also save or display the cropped image. The cropping can be done in 9 different positions: top left, top, top right, left, centre, right, bottom left, bottom, or bottom right. Or you can have it automatically cropped based on a threshold value. The original image can be loaded from the file system or from a string (for example, data returned from a database.) Not only all that, but it also comes with a drag & drag web interface for exceptional ease of use.