Patent ID: 7606423

Claim:
A method comprising: receiving a video signal from a video signal source, the video signal source being a video tuner, a satellite earth station or a DVD player; detecting vertical edge pixels in an image in the video signal; analyzing said detected vertical edge pixels by horizontal location in said image to detect a spatial periodicity in said detected vertical edge pixels; detecting horizontal edge pixels in said image; analyzing said detected horizontal edge pixels by vertical location in said image to detect a spatial periodicity in said detected horizontal edge pixels; post-processing said image based on results of said analyzing steps; and displaying said post-processed image on a display device; wherein: said detecting vertical edge pixels includes, with respect to a target pixel: calculating a first difference Δ 1 as an absolute value of a difference between a value of the target pixel and a value of a first pixel that is immediately to the left of the target pixel; calculating a second difference Δ 0 as an absolute value of a difference between the value of said first pixel and a value of a second pixel that is immediately to the left of the first pixel; calculating a third difference Δ 2 as an absolute value of a difference between the value of the target pixel and a value of a third pixel that is immediately to the right of the target pixel; and classifying the target pixel as an edge pixel if and only if all of the following conditions are met: (a) the first difference Δ 1 is less than a threshold; (b) the first difference Δ 1 is greater than the second difference Δ 0 ; and (c) the first difference Δ 1 is greater than the third difference Δ 2 .