Fast mode decision algorithm for HEVC screen content intra coding

Screen Content coding (SCC) is one of an extension to High Efficiency Video Coding (HEVC) developed by the Joint Collaborative Team on Video Coding (JCT-VC). It adopts two new coding tools, intra block copy (IBC) and palette (PLT) modes, to improve the compression performance for intra coding. Nevertheless, mode selection causes a substantial increase in encoding complexity. In this paper, a fast mode decision algorithm, which makes use of early mode skip decision based on the Bayesian decision rule using online learning, is proposed. The proposed algorithm is implemented in the SCC reference software SCM-7.0. Experimental results show that the proposed algorithm can achieve 23.2% complexity reduction on average with only 0.58% Bjontegaard delta bitrate loss in All Intra (AI) configurations.