Patent ID: 7432987

Claim:
A method of motion detection for a 3D comb filter video decoder, comprising: sampling a composite video signal for obtaining a plurality of temporarily stored sampled data F m P x,y , wherein F m P x,y represents a sampled data of a y th pixel on an x th line of an m th frame in the composite video signal, and m, x, y are positive integers greater than or equal to 0, wherein the composite video signal is a signal for a PAL system, a frequency which is 4 times the subcarrier frequency in the composite video signal is used to sample the composite video signal, and the composite video signal is sampled when the subcarrier phase is equal to 0.25π, 0.75π, 1.25π, and 1.75π; and using F m+1 P x,y , F m P x,y , F m−1 P x,y , and F m−2 P x,y to determine a motion/still status of the composite video signal, comprising: using F m+1 P x,y , F m P x,y , F m−1 P x,y , and F m−2 P x,y to calculate and obtain a plurality of max differences MD x,y , wherein MD x,y represents a max difference of the y th pixel on the x th line; averaging 4 max differences of the contiguous pixels selected to obtain a motion factor MF x,y , wherein MF x,y represents a motion factor of the y th pixel on the x th line; and detecting MF x,y to determine the motion/still status of the y th pixel on the x th line in the composite video signal, wherein the step of calculating and obtaining MD x,y further comprises: calculating and obtaining a plurality of luma differences LD x,y , wherein LD x,y represents a luma difference of the y th pixel on the x th line, and is calculated based on an equation: LD x,y =|F m P x,y +F m−2 P x,y −F m+1 P x,y −F m−1 P x,y |; calculating and obtaining a plurality of intermediate differences IMD x,y , wherein IMD x,y represents an intermediate difference of the y th pixel on the x th line, and is calculated based on an equation: IMD i,2j−1 =Max{| F m+1 P i,2j−1 −F m−2 P i,2j−1 |, |F m P i,2j−1 −F m−1 P i,2j−1 |}; IMD i,2j =Max{| F m+1 P i,2j −F m P i,2j |, |F m−1 P i,2j −F m−2 P i,2j |}; and calculating and obtaining MD x,y , which is calculated based on an equation: MD x,y =a*IMD x,y +(1− a )* LD x,y ; wherein, a is a real number greater than 0 and less than 1, and i, j are positive integers.