US Patent 7251064 Calibration of an image scanning system

A calibration method of an image scanning system is provided. Initially, differences between adjacent sensing values of a calibration plate are respectively determined and then stored in a memory. Alternately, a difference between a base value and each of the sensing values of the calibration plate is determined and then stored in the memory. When a normal scan action is executed, simultaneously reading each difference from the memory and adding to one corresponding sensing value of image information of an object obtained by the normal scan action. As a result, the memory volume for storing calibration data is reduced and the reading of calibration data is also facilitated.