Android OpenCV Find Largest Square or Rectangle

Question

This might have been answered but I desperately need an answer for this. I want to find the largest square or rectangle in an image using OpenCV in Android. All of the solut

Answer 1

There are some related questions here in SO. Check them out:

• OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection

• How do I recognize squares in this image?

There is also an example shipped with OpenCV:

• https://code.ros.org/trac/opencv/browser/trunk/opencv/samples/cpp/squares.cpp?rev=4079

Once you have the rectangle, you can align the picture by computing the homography with the rectangle corners and applying a perspective transform.