Calculate Angle Of Rotation Image Wrt Another Image

I am developing an application which processes cheques for banks. But when the bank's image of a cheque can be skewed or rotated slightly by an angle of maximum value 20 degrees. B

Solution 1:

What I would do in your case is to find the check within the image using feature matching with your template check image. Then you only need to find the transformation from one to the other and deduce the angle from this.

Take a look at this OpenCV tutorial that teaches you how to do that.

EDIT:

In fact, if what you want is to have the bank check with the right orientation, the homography is the right tool for that. No need to extract an angle. Just apply it to your image (or its inverse depending on how you computed it) and you should get a beautiful check, ready for processing.