An Adaptive De-blocking Method based on Measuring Flatness of Macroblock

Block artifact is a serious problem which generally emerges in video or image compression system based on block. In H.264, strength, a value which indicates the degree of block artifact, is obtained by the prediction mode, reference frames and motion vectors. However, in some cases, the de-blocking method in H.264 is not so satisfactory because of the ignorance of image behavior. According to the research of HVS (human visual system), the blockiness in flat region is much more easily observed than that in complicated region. Thus, it is needed to evaluate the flatness of a particular region so as to measure the strength of blockiness. In this paper, a de-blocking method which is based on the flatness of two adjacent blocks is proposed. In the experiment, it is proved that this flatness-based de-blocking method has more superior performance than the traditional one in H.264