A new method exists for de-skewing documents through the use of grayscale image data. This technique has significant quality advantages over approaches which de-skew using binary image data. It also has significant cost and reliability advantages over some more complex mechanical de-skew approaches.
This white paper explores the problem of document de-skewing in general and then discusses the advantages of grayscale de-skewing in document imaging.
The recommended approach is a hybrid of any simple, reliable mechanical approach to minimize skew (as offered by most current production-speed document scanners) followed by the use of the grayscale de-skew technique to remove what skew remains.