Jungsun Kim

Improved palette index map coding on HEVC SCC

Palette mode is the new coding tool that has been adopted in the Screen Content Coding Extensions of High Efficiency Video Coding (HEVC SCC). Palette mode can represent colour clusters for screen content efficiently and can be summarized into two parts: palette coding tools and colour index map coding tools. This paper proposes two techniques to improve colour index map coding: transition copy and prediction across coding unit boundary. The former is for exploring the correlation between an index and all of the previously coded indices; the latter for utilizing the correlation between the content along the coding unit boundary. Experimental results reportedly show that, compared with HEVC SCC, the proposed techniques can achieve 3.2%, 2.2%, and 1.7% BD-rate savings compared with HEVC SCC for “YUV, text & graphics with motion, 1080p & 720p sequences” under all intra, random access, and low-delay B common test conditions, respectively.

Improvements of HEVC SCC Palette Mode and Intra Block Copy

Palette mode and intra block copy are two new coding tools that have been adopted in the screen content coding extensions of high efficiency video Ccoding (HEVC SCC). Palette mode can represent color clusters for screen content efficiently. Intra block copy (IBC) facilitates block prediction within the same frame. Both tools have demonstrated promising benefits for screen content coding. In addition to HEVC SCC, this paper introduces five new coding techniques to enhance palette mode or IBC: transition copy, prediction across coding unit boundary, advanced motion vector coding, modified temporal merge candidate derivation, and new default IBC merge candidates. Experimental results show that the proposed techniques can achieve 5.4%, 5.2%, and 4.9% BD-rate savings compared with HEVC SCC for “YUV, text & graphics with motion, 1080p & 720p sequences” under all intra, random access, and low-delay B common test conditions, respectively.