I'm trying to align scans to a blank template -- images are from the same scanner at same scale, just rotated and translated. I find ORB feature matching as described here.
I've had good luck using findHomography and then sending that homography matrix to warpPerspective. However, findHomography allows more degrees of freedom than necessary; We just do rotation and translation, no scaling.
estimateAffinePartial2D gives me a 3x2 matrix -- How can I determine the rotation, translations (x&y) , and the scaling contained in that matrix? That way, if scaling is not close to 1, I know the homography is bad.
Is there a way I can FORCE the estimateAffinePartial2D to find only solutions where scaling 1???