This chapter provided a brief introduction to what you can do with images and PHP. The "Image Functions" section of the PHP manual, at http://www.php.net/image, is highly recommended not only for a complete list of image-related functions but also for examples and discussion about their use in your applications.
In this chapter, you learned about installing and using additional libraries for working with imagesthe examples used PNGs, but you were given instructions for using GIFs and JPGs as well. You learned the basic steps for creating an image canvas and allocating color, and for drawing and filling shapes. You learned that your drawing canvas can consist of an existing image and that you can merge layers so that a final image is a composite of the layers that have been merged. Additionally, you saw how simple it is to use input from users (in this case, from an HTML form) in your image creation scripts.