PHPit.net has posted part one of a new series of tutorials focusing on working with the GD graphics library inside of PHP.
In this new article series you will learn about PHP's inbuilt image functions. In the first part you will see how to open images, display or save them, and how to write a simple image converter.
They start with a look at reading images in to start working with, in both GIF and JPEG formats. To make things simpler for life down the road, they opt to create their own simple "open_image" function that adapts to whatever kind of file it's given and returns an image resource.
Then it's over to the output - displaying and saving the images out to a local drive. Finally, they demonstrate how to convert images from one file type to another (as uploaded via a HTML form).