This is a script that transforms a black and white simple drawing into a map like image with grass and sea. I tested it only on my machine, and it take several seconds to run and create a reasonable looking figure. All my tests where tried on a 500x500 image with 200x200 dpi resolution.
My machine (the only one I tested this on) is Lenovo edge. It has a i3 processor (don't remember the exact model) and 6GB of RAM. I run Ubuntu 13.04 and gimp 2.8.4 on it.
How to use.