Fast intra mode decision and block matching for HEVC screen content compression

Abstract

Screen content coding (SCC) is the latest extension of the High-Efficiency Video Coding (HEVC) aiming to improve the compression efficiency of screen content video. With newly developed tools such as intra block copy (IntraBC) and palette (PLT) mode, SCC has been able to compress the desktop screens more efficiently but with significant complexity increase. In this paper, we improve the intra prediction from two aspects. Firstly, by leveraging the temporal correlation among coding units (CU), we develop a fast CU depth prediction scheme. Furthermore, adaptive search step is employed for further speed up of the time-consuming block matching in IntraBC. The overall encoding time is reduced by about 39% and 35% for the All Intra (AI) lossy and lossless encoding scenarios with negligible quality loss under the SCC common test condition.