Hi everyone! Thanks for following my project! I'm migrating it to Elephant AI now! This is for a new entry to the Hackaday 2017 prize! And it is a bit confusing too, as lots of my earlier plans for hardware and software here have been superseded! I can't believe I was thinking just histogram comparison or feature matching with FLANN would work!
You can find the Elephant AI project here -> https://hackaday.io/project/20448-elephant-ai