The PNGwriter library, which requires libpng, allows
you to plot to a 48-bit PNG file, saving it
directly to disk. Plotting is as easy as
specifying the red, green, and blue values and the
x, y coordinates of the pixel. It includes
functions for plotting simple geometric shapes
(circle, rect, line), plotting text (UTF-8 support for Asian languages), reading the colour of a
pixel, reading in a whole PNG file (great for
image analysis), plotting and reading in HSV
colourspace, and many others that might come in handy.
