gd is a graphics library. It allows your code to quickly draw images complete
with lines, arcs, text, multiple colors, cut and paste from other images, and
flood fills, and write out the result as a PNG or JPEG file. This is
particularly useful in World Wide Webapplications, where PNG and JPEG are two
of the formats accepted for in-line images by most browsers.

gd is not a paint program. If you are looking for a paint program, you are
looking in the wrong place. If you are not a programmer, you are looking in the
wrong place.

gd does not provide for every possible desirable graphics operation. It is not
necessary or desirable for gd to become a kitchen-sink graphics package, but
version 1.7.3 incorporates most of the commonly requested features for an 8-bit
2D package.