Adaptive parameter for Canny Edge

Question

I\'m using a project using OpenCV for detecting a card that will be place on a atable. I have successfully detect it using Canny Edge. However, for different image the param

Answer 1

You can use Helmholtz principle to adaptively find the lower and higher thresholds of the Canny edge detector.

You can refer the following link for the paper and the implementation in OpenCV C++.