A Post Deblocking Filter for H.264 Video

For very low bit rate video coding, coarse-quantized DCT coefficients induce discontinuities at block boundaries, namely, blocking artifacts. Furthermore, motion-compensated prediction propagates blocking artifacts to inner-block regions of subsequent video frames. Blocking artifacts caused by motion-compensated prediction (MCP) can be solved by a loop-filter. The main drawback of loop-filter is its in-flexibility. In this study, a post deblocking filter for H.264 video is proposed. In this study, to estimate inner-block discontinuities, a motion-compensated based approach is proposed. A map of detected blocking artifacts within each video frame is stored. Combining motion vectors and blocking artifact maps of previous frames, possible locations of blocking artifacts can be estimated. Cooperating with oriented blocking artifact detection and filtering, a post deblocking filter having loop-filter performance is established. The proposed approach can also used in other DCT/MCP based codecs.