A port of the php script by Andreas Gohr (http://www.splitbrain.org/projects/monsterid). Actually kinda more like a rewrite.
After version 0.4 only ChunkyPNG is required, thus MonsterID now only requires pure ruby. :) If OilyPNG is available, MonsterID will load it, and be as fast as before. Make sure OilyPNG is at least v1.2.1, as <=1.2.0 has a bug with transparency.
Feel free to use/steal/share/improve.
require 'monsterid'
monster = MonsterID.new('[email protected]')
print monster.id # SHA1 of seed
monster.save("~/monsters/#{monster.id}.png") # monster
print monster.to_datastream # Prints raw PNGCopyright (c) 2014-2017 Knut Aldrin. See LICENSE for further details.