Corner detection in Python OpenCV for extraction of squares

Question

I am working on a form extraction module which detects text in specific segments of an image. So far I am able to remove the text and retain only the bounding box in the image.

My next step was to extract each box in the image. To do that I am trying to detect corners in the image. But here is where I am stuck. I tried template matching. This was the result. Although the results look promising the drawback is that this method is very time consuming. And few corners are still not detected.

I also tried Shi-Tomasi Corner Detector after dilating the image.

What would be the best approach to solve this problem?

Answer 1

I suggest you detect the lines instead, e.g. using Hough transform, followed by edge chaining, followed by robust line fitting on each chain.