Mode dependent intra smoothing filter for HEVC

High efficiency video coding (HEVC) is the latest video coding standard, in which coding performance improvement of intra prediction comes from flexible block partitioning and advanced directional prediction. Blocks with strong directionality and regular patterns can be handled well by this finer granular directional prediction. However, irregular patterns and noises often exist in natural videos, and reference samples are not fully used in directional intra prediction. In this paper, we propose a mode dependent intra smoothing filter algorithm to improve intra prediction, which employs a Markov model to improve coding efficiency of intra prediction. Experimental results demonstrate that the proposed method can achieve average 1.1% (up to 1.8%) BD-rate reduction in all intra high efficiency test condition compared to HM 16.0.