Intra Block Copy for HEVC Screen Content Coding

Screen content videos increasingly gain the popularity due to the rapid advances in cloud and multimedia technologies, which in turn requires highly efficient screen content compression. A recent standard, namely SCC is under development in JCT-VC, Joint Collaborative Team on Video Coding between ISO/IEC and ITU-T. In SCC, the most efficient new coding tool is Intra block copy (Intra BC). In this paper, we describe the Intra BC that has been proposed by the authors and adopted in the SCC standard and reference software for coding of screen content. Different from the conventional Intra prediction method where the prediction signal is derived from the spatially neighboring samples, the Intra BC mode greatly improves the prediction efficiency by fully exploiting the redundancy of repetitive patterns which typically appear in screen content. Experimental results suggest that the Intra BC mode can improve the coding efficiency significantly for typical screen content video sequences with 43.2% bit rate reduction on average.