This is a really old image library/class thing I wrote back in Summer 2006 while working with Jeremy and his company. I believe it was originally written in PHP4 and updated to PHP5 a month or two after the original was written. There are some features, like drawing rotated images/ellipses, that were commented away due to them not working on PHP4, but may work now if someone dares to try. 
The comments are fairly plentiful, and I’m feeling lazy, so it shouldn’t need a manual to get started (besides, I haven’t used it in years either).
The code is located at http://gist.github.com/429474
To this day, I still believe encode_string_to_image and decode_image_to_string are the coolest part of this whole class.