Topics in This Chapter
Most of the functions described in this chapter require the gd extension or the exif extension. The functions from the gd extension begin with image, have no underscores, and require the GD library. The exif functions begin with exif_.
Other functions in this chapter require the GD library plus one or more additional supporting libraries. For example, in order to read and write JPEG images, you need the JPEG library. Consequently, these functions may not be available to you, depending on how PHP was compiled.
The GD library was created at Boutell.com, a company that has contributed several Open Source tools to the Web community. The library historically supported ...