Image matching
From Open Maps wiki
Looking at SIFT implemented on phone with JavaScript - doesn't look like it's out there.
SIFT on Raspberry Pi would be too slow.
ASIFT online processing looks okay, but slow.
Octagon matched on structure and colour (quite well) but not useful. Need SIFT
Just do desktop matching and keep a copy of the database?
Or even just ask people to tag the image with some descriptive words or whatever the text is!
