GD.pm is a autoloadable interface module for libgd, a popular library
for creating and manipulating PNG files. With this library you can
create PNG images on the fly or modify existing files. Features
include:

a. lines, polygons, rectangles and arcs, both filled and unfilled
b. flood fills
c. the use of arbitrary images as brushes and as tiled fill patterns
d. line styling (dashed lines and the like)
e. horizontal and vertical text rendering
f. support for transparency and interlacing