Patent ID: 8295633

Claim:
A method of reducing video artifacts due to compression noise, comprising: decoding data representing a compressed image of the video; locating block boundaries in the decoded image; estimating the strength of the artifacts, determined from data representing the decoded image, on the block boundaries; smoothing at least one section of the block boundaries having artifacts, wherein the amount of smoothing is based on the strength of the artifacts detected in the section, includes: smoothing performed based at least in part on a quantization level formed by combining a first value taken from data representing an encoded sub-block and a second value estimated based on a plurality of block edge statistics derived from data representing a decoded sub-block, the plurality of block edge statistics includes: calculating the plurality of block edge statistics, determined by the video intensities of the pixels of sub-block, which comprise a block edge metric, a block ratio metric, a block count metric and a block activity metric, forming a weight factor from values of the block edge statistics by mapping to an interval extending from zero to one using a weighting function specific to that metric, and forming a composite weight factor the indicative of the strength of the compression noise in the sub-block by multiplying the weight factors together, replacing at least one section of the block boundaries having artifacts with the smoothed version of the section; and wherein the weight factors are multiplied together to form a composite weight factor indicative of the strength of the compression noise in the sub-block.