1. A method of performing an affine transformation including at least one of a shear revision and a skew revision in an image processing system that processes an image, the method comprising: obtaining at least one of an image shear value and an image skew value; determining whether the least one of the image shear value and the image skew value is within a predetermined range; obtaining at least one of a weighted average shear value and a weighted average skew value from a memory device; updating the at least one of the average shear value and the average skew value based on the at least one of the image shear value and the image skew value if the at least one of the image shear value and the image skew value is within a predetermined range; and storing the updated at least one of the average shear value and the average skew value in the memory device.