Class Upload PHP is a script written in PHP language, whose function is to be able to upload images to a server, and from there edit them or apply some modification. For example, change the size, convert its graphic format, insert a watermark, or whatever you can think of.
The Class Upload PHP script makes use of the GD graphics library, so the formats it supports are the same as are supported by the library: PNG, JPEG and GIF. Other basic actions include cutting set zones of an image, negatives, grey scale, rotation, borders, modify parameters like brightness, contrast etc.