I'm using OpenCV and ZBar with python to make some QR Code detection and, for my specific application, I have to address the following problem:
even if I'm not able to decode the QR code, maybe because it is blurred or partially covered by something, I want to know if there are good chances that I've found a QR Code. For example, I guess it should be not hard to understand if the image contains two out of three of the "squares" in the corners of a QR Code. Of course the detection of the corners is a step that zbar has to perform before being able to decode, but I don't know if there is actually a way to get such "intermediate" information when I can't get a complete result.
I don't necessarily have to use Zbar. If you have any suggestion to solve this problem, I'd be very thankful.