No subject

functionality. The demo demonstrates one way of getting rendered
surface data into a PNG. One could just as easily do the same for
JPEGs with jpeg62.

There are plenty of image I/O libraries offering a wide variety of
features and formats. You might try GdkPixbuf for starters from the Gtk
project. This is fine if glib is a dependency of your project anyway.
You should search freshmeat for others. Using libpng or jpeg62 directly
is of course viable, and you can write a fairly generic read routine for
both these libraries in about 130 lines. Depends on what you need really:
supported formats vs. small footprint.