Patent ID: 7539248
Filing Date: 2009-05-26
Classification: H04N

Abstract:
1. A method for filtering a video stream to reduce a blocking artifact in a post-processing de-blocking device of a video decoder, the method comprising: calculating an activity value representing local activity around a block boundary between a plurality of adjacent blocks in the video stream; determining a region mode according to the activity value; utilizing a threshold determination unit for determining a plurality of thresholds; the thresholds taking into account a user defined offset (UDO) allowing the thresholds to be adjusted according to the UDO value; utilizing a de-blocking filtering unit for filtering a plurality of pixels around the block boundary according to the region mode and the thresholds; at least taking into account differences in quantization parameters QPs of the adjacent blocks to determine a first threshold, a third threshold, a fourth threshold, a fifth threshold, a sixth and a seventh threshold utilizing the threshold determination unit; if at least one of the adjacent blocks is an intra-coded block: if none of the adjacent blocks are intra-coded blocks: