Why are you committing to a language before you know what technologies are available? I would think it would make more sense to see which technologies support something like this, and then choose the best one for your needs.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
This is a very complex task, techniques are usually described in academic papers. I think you're best off using third party libraries. Facebook even bought an entire company that specialized in facial recognition.
You should never use facial recognition for authentication purposes though. It's easily fooled unless you manage to write an extremely sophisticated algorithm that requires three dimensional movement.
Get out of my mind! Look! A tiny ad!
how do I do my own kindle-like thing - without amazon