Graffiti is recognized by observing the strokes (direction, turns, etc) as it is drawn, with each pen lift/touch marking the characters. This is quite a differe

Graffiti is recognized by observing the strokes (direction, turns, etc) as it is drawn, with each pen lift/touch marking the characters. This is quite a different problem from doing OCR on it in a photograph, where you can (hopefully) see the shapes, but you do not know where the strokes began and ended.