Patent ID: 7054367
Filing Date: 2006-05-30
Classification: H04N

Abstract:
1. A method of detecting edges in a compressed video sequence, the compressed video sequence including at least one frame of block encoded video data, the frame of block encoded video data including variable-length codes for transform coefficients of blocks of pixels in the compressed video sequence, the transform coefficients including a respective DC coefficient for each of the blocks of pixels, each respective DC coefficient for at least some of the blocks of pixels being encoded as a respective variable-length code having a length indicating a certain range of differences in DC coefficient values between adjacent ones of the blocks of pixels, wherein the method comprises: decoding only the length of the respective variable-length code for the respective DC coefficient for each of said at least some of the blocks of pixels in order to produce an indication of whether or not the compressed video sequence includes an edge associated with said each of said at least some of the blocks of pixels; and performing a code length threshold comparison upon the length of the respective variable-length code for the respective DC coefficient for said each of said at least some of the blocks of pixels for producing at least one respective bit indicating whether or not the compressed video sequence includes an edge associated with said each of said at least some of the blocks of pixels.