The blog page refers to this mapbitter tool that is distributed as windows executable (+jar). Running java -jar MapBitter.jar lovelyearth.bmp on my Linux gives me a trace:
I will do my best to process: lovelyearth.bmp for you
Exception in thread "main" java.lang.IllegalArgumentException: input == null! at javax.imageio.ImageIO.read(ImageIO.java:1388)
at MapBitter.processImage(MapBitter.java:22)
at MapBitter.main(MapBitter.java:18)
It would be awesome to get this working on Linux too.