Patent ID: 8094235

Claim:
A method of image signal processing comprising: calculating a first threshold based on a first set of motion values, generated prior to a first time, corresponding to an image input signal when the image input signal is detected to be a film mode at the first time; generating a second threshold according to the first threshold and a first offset value; generating a third threshold according to the first threshold and a second offset value; calculating a second set of motion values corresponding to the image input signal between the first time and a second time; comparing at least one motion value of the second set of motion values with the second threshold, and comparing remaining motion values of the second set of motion values with the third threshold, for generating a field variation judge value series; and comparing the field variation judge value series with a film-mode cadence sequence for determining whether the image input signal between the first time and the second time is the film mode or a video mode; wherein the second time is behind the first time.