I’ve been experimenting with using Markov Clustering at work. It’s a very nice algorithm for clustering certain classes of symmetric graphs.

I had a vaguely interesting thought: What, thought I, if I took an image and built a graph out of its pixels. The edges would go between nearby pixels and would be weighted according to the similarity of their colours. We could then markov cluster that and see what the results looked like.

Well… the results are amusing. There’s some interest in them, but mainly in what it say sabout how markov clustering works. Behold, as we turn this:

Into this:

Hmm. Back to the drawing board.

I’ve dumped the code here if you’re at all curious.