Form registration: a computer vision approach

In this paper, a technique for extracting the distortion parameters in filled-in forms is presented. The technique determines the transformations that are required to convert a filled-in form to match a known master and then extracts filled-in information. The method involves determining corresponding lines and key points between the master and the filled-in form and using the correspondence to determine the appropriate transformation. The correspondence problem is solved using results from affine geometry.