Open Source way to real-time image processing OCR application? [closed]

Question

I have an application in mind that I want to produce. We have wall-mounted schedule boards that are divided into small rectangles using black lines on a white background. Magnetic name tags are placed into a particular partition to indicate this person is to work in that cell. This system works very well for communication among people, but I would like an automatic way of saving this schedule information into a database automatically.

I am envisioning a system where a camera is set in a fix position focusing on the schedule board. Periodically the camera will take a picture of the board. I want to write some code to decipher which name tags are in which area. This would require some OCR or symbol recognition. There are big numbers on each name tag that I will use to identify the person whose name tag it is.

I naturally go to Python when tackling a new programming problem. I found this post -> python image recognition which looks like a good place to start (with PIL and numpy).

Do you know a good way to do this?

Update: I have tried SimpleCV and it seems good for now.

Answer 1

This is actually a pretty hard problem, even though it looks quite simple. But you can make it a lot easier by doing some stuff to your image to make this manageable. I have the following suggestions:

• Try to make it so that your camera is looking straight at the board with a reasonable lens so that there is minimal distortion of the image on the edges, and no perspective distortion.
• Given that you'll be shooting the occasional image for analysis I think performance is in no way an issue, so shoot high-resolution images, with a flash or with a long exposure time (because everything you're shooting is stationary) to get the best possible picture quality.
• If the number of different tags you expect is not too large you might find it easier to just try to match reference images of these tags in your image through template matching rather than going for full OCR of numbers. This is a lot easier to get working if your image is good enough. The python opencv interface is very complete.
• High Performance Mark has a good comment to your question about including barcodes on the tags. I would add the option of QR codes, but that is just the same thing. Both are easy to detect and there are good libraries to help you read them.
• If you decide you do need OCR, you should look into available OCR packages and not try to roll your own. Try pytesser for the tesseract engine or the OCRopus python interface.