Non-local Structure-based Filter for Video Coding

The deblocking filtering (DF) in HEVC is only applied to the boundaries between the coding units, prediction units, or transform units, which actually exists two issues. On one hand, the simple DF in HEVC does not fully exploit structure information in video. On the other hand, DF in HEVC does not consider the inside areas, which often suffers from quantization distortion. To alleviate the above issues, in this paper, a non local structure-based filter (NLSF) is proposed by simultaneously enforcing the intrinsic local sparsity and the non-local self similarity of each frame in video. NLSF not only deals with the boundaries, but also deals with the inside areas, which is able to effectively reduce the artifacts while enhance the quality of the deblocking frames. Experimental results demonstrate that, compared with the original HEVC reference encoder implementation in AI configuration, the proposed NLSF can achieve up to 7.3% BD-rate saving by substituting for DF in HEVC.