Search a photo for drawing

Question

I want to be able to do something like take a picture of a chalkboard and search for what the teacher wrote and then delete the chalkboard and make like a CGContext Path of what the teacher wrote, or just have what the teacher wrote

Answer 1

OCR is tricky with the iPhone camera. If you just want to pull out edges and save those you might try a Canny edge detector followed by a little edge linking to get larger features. You'll get some noise though, off a chalk board.

Easiest approach to that would be to use OpenCV. You can grab a version that's already been ported and compiled from this guy's site: http://niw.at/articles/2009/03/14/using-opencv-on-iphone/en

My sense is that this approach is probably not quite right for what you want. I'd sit down and think a bit more about what you're trying to do.

Answer 2

You might want to look at OCR.

Here is one option: Mobile OCR Engine for iPhone app