Very cool. Images like this are fairly popular in woodworking for low poly pet art:
https://www.reddit.com/r/woodworking/comments/7vcgar/boyfrie...
(search "low poly" on /r/woodworking for a lot more)
DMesh is probably the most popular tool in this space that I've seen, but it's a very manual process (manually select vertexes and it fills the space with the average color).
Yours definitely gives a different look - a bit more aliased - which is interesting. Would be fun to try this one out too.