It looks like this script uses the image it's writing to as part of the algorithm(extending pixels until they hit rooms, etc.)<p>For more complex maps, it might be worth using something like DOT to define the abstract graph, and use any image generator tools to layout the dungeon. As a bonus, it would generate curved hallways to link the rooms.<p><a href="https://en.wikipedia.org/wiki/DOT_(graph_description_language)" rel="nofollow">https://en.wikipedia.org/wiki/DOT_(graph_description_languag...</a><p>You seem to have specific requirements for the image to be easily loadable into a Voxel engine, so it may be that this method wouldn't be useful.
I started running some games of Paranoia last winter, and found this tool to be quite useful for generating layouts: <a href="http://donjon.bin.sh/fantasy/dungeon/" rel="nofollow">http://donjon.bin.sh/fantasy/dungeon/</a><p>There is also a pure-JS version which works offline, downloadable from here: <a href="http://donjon.bin.sh/apps/" rel="nofollow">http://donjon.bin.sh/apps/</a>
I wrote a VB dungeon generator from Appendix C: Random Dungeon Generation Tables in the Advanced Dungeons and Dragons Dungeon Masters Guide back in the day. It made some totally awesome dungeons and output them in a bmp that had a light-blue grid, black dungeon walls and floodfill areas in the rooms and halls. It compiled a complete legend of room contents, door information, trap information, etc., and output that as a text file. I will have to search and see if I can find it.