Fast intra-prediction for lossless coding of screen content in HEVC

The High Efficiency Video Coding (HEVC) standard achieves higher encoding efficiency than previous standards such as H.264/AVC. One key contributor to this improvement is the intra-prediction method that supports a large number of prediction directions at a cost of high computational complexity. Within the context of mobile devices with limited power and computational capabilities, reductions on encoding complexity are important; particularly to encode new data formats such as screen content sequences. This paper presents a novel intra-prediction method for lossless coding of this type of sequences. The method employs one of three possible intra-prediction modes to encode each prediction block. These three modes predict strong edges, model different directional patterns and generate smooth surfaces. The proposed method provides a decrease of up to 53.84% in the HEVC intra-prediction lossless encoding time, with average bit-rate reductions of 7.05% for a variety of screen content sequences.