Low-Complexity Intra Coding for Scalable Extension of HEVC Based on Content Statistics

This paper presents a new approach for a scalable extension of High Efficiency Video Coding (HEVC) intra pictures. The proposed scalable intra codec targets very low complexity together with coding efficiency, and thus employs only one prediction mode, known as inter layer intra prediction. The main novelty of the codec is a new fast rate-distortion optimization approach, which is founded on the rate-distortion theory. It exploits precomputed offline information for the reduction of the computational complexity, and a new allocation process for the balancing of the coded information. The precomputed information is a set of optimal quantifiers and associated rate-distortion curves for predetermined statistical models that are used for efficiently coding the Discrete Cosine Transform channels. This low-complexity intra coding tool has been proposed to the scalable HEVC call for proposals. In the scalable standard testing conditions, the proposed intra codec shows compression performance with a bit-rate increase of around 10% only compared with the HEVC single-layer encoder.