RDO Cost Modeling for Low-Complexity HEVC Intra Coding

High efficiency video coding (HEVC) is the newest international standard for video compression, providing improved coding performance that achieves compression ratios up to 50% higher than those obtained with H.264/AVC. However, this improvement comes at the expense of high computational complexity and coding time. In this paper, we propose a novel method for fast and low-complexity intra HEVC mode decision based on rate-distortion optimization (RDO) cost modeling, which permits the exclusion of non-promising candidates from the RDO processing. To achieve even more complexity reduction, an additional rough most probable modes examination is coupled with the main algorithm. Experimental results show that the proposed algorithms reduce the encoding time by 41.8% on average, with a negligible quality loss of 0.058 dB (BD-PSNR) for all-intra scenarios, as compared to the HEVC reference implementation, the HM 15.0.