Patent ID: 8224033

Claim:
A movement detector, comprising: A frame delay unit receiving a composite signal to generate a one-frame delayed signal, a two-frame delayed signal, and a three-frame delayed signal; a first combiner for generating a first difference from a first pair of the composite signal, the one-frame delayed signal, the two-frame delayed signal, and the three-frame delayed signal; a second combiner for generating a second difference from a second pair of the composite signal, the one-frame delayed signal, the two-frame delayed signal, and the three-frame delayed signal, wherein the second pair is different from the first pair; a third combiner for generating a third difference for detecting motion based on the first difference and the second difference; and a first in-phase selector for generating an output of the first in-phase selector according to whether an absolute value of the first difference is in-phase, wherein an output of the first in-phase selector is equal to the absolute value of the first difference if two signal in the first pair are in-phase; otherwise, the output of the first in-phase selector is equal to zero.