views:

62

answers:

2

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

A: 

You might want to look at OCR.

Here is one option: http://stackoverflow.com/questions/1722269/mobile-ocr-engine-for-iphone-app

Daniel A. White
OCR - Optical Character Recognition.
Daniel A. White
What does OCR do, and does it work on the iPhone?
Jaba
OCR is a technology to detect text in an image and convert it to text.
Daniel A. White
Does it work on the iPhone?
Jaba
A: 

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.

mousebird
Is it free and can I sell my app with openCV in it?
Jaba
The license is fairly friendly. I don't see why not.
mousebird