Cameraplus does face recognition in photos, and source is on github. Don't know if it implements face detection itself or uses API, but might be worth a look-see . . .

Thank you. I hoped you'd find my advice helpful, but "delightful" is far above expected reaction scale

So, the next logical step would be applying a real tiger to the problem, possibly multiple times: once to get known to local c. population, then periodically to remind. Between those times you'd have the garden all to yourself. Getting rid of tiger (or multiple tigers) is left as as an exercise to reader; as for getting it to appear, there's a thread about importing phones from India -- maybe the channel, once established, can be used to other goods as well?

Maybe find a patch of land nearby and plant a catnip there, to attract c.s out? Or just get a dog *)

*) dog - better than cat (http://manpages.ubuntu.com/manpages/...an1/dog.1.html)

And now, for something more ontopic: most opensource image recognition solutions are related to OpenCV. See Face Recognition with OpenCV for simple examples and OpenBiometrics site for more polished tools.