# How can I find rotation angles (pitch, yaw, roll) from perspective transofmation coefficients?

I have two 2d quads (each represented using 4 xy pairs), one of them is a perspective transformation of the other. How can I use these quads to deduce the rotations (pitch, yaw, roll) that caused the perspective distortion?

Notice that I used the cvGetPerspectiveTransform() which returns the perspective transformation coefficients in the form of a 3x3 matrix. I am able to use such coefficients to map a point from one space to another. However, it is the rotation angles which I'm concerned about knowing.

Any ideas?

Thanks, Hasan.