DevShed continues its look at using the GD graphics library in PHP with the second part of the tutorial series, this time focusing on the creation of images from existing images (and their streams).

As I stated at the end of the previous article of this series, the GD extension comes packaged with many other useful functions, which indeed deserve a close and detailed look. Thus, in this second tutorial I'll show you how to create different types of image streams from existing graphics, but in this case limiting the process to building GIF, JPG and PNG images.

They work through each of the types (GIF, JPG and PNG) creating an new one from a previous "clouds" image of the same type (a GIF out of a GIF, a JPG from a JPG, etc).