Fast Algorithm with Palette Mode Skipping and Splitting Early Termination for HEVC Screen Content Coding

Screen content videos have special features such as frequently repeated patterns, limited number of colors and non-noisy regions. It differs from the natural scene sequences which require more proper coding tools. New modes were incorporated into the High Efficiency Video Coding (HEVC) standard such as Palette mode (PLT) and Intra Block Copy (IBC) to target the special nature of theses videos. The new tools achieve higher coding performance, however, they bring remarkable computational complexity. In this paper, a new fast scheme is proposed to reduce the HEVC encoding time for the screen content videos. It depends on the number of distinct colors inside the current block. The new approach is implemented and simulated using HEVC screen content extension software HM 16.7+SCM 6. The results show that our scheme reduces the encoding time by 24.46 % with small increment of 2.1 % in the bitrate.