The Range Extensions (RExt) of the High Efficiency Video Coding (HEVC) standard have recently been approved by both ITU-T and ISO/IEC. This set of extensions targets video coding applications in areas including content acquisition, post production, contribution, distribution, archiving, medical imaging, still imaging, and screen content. In addition to the functionality of HEVC Version 1, RExt provides support for monochrome, 4:2:2 and 4:4:4 chroma sampling formats as well as increased sample bit depths beyond 10 bits per sample. This extended functionality includes new coding tools with a view to provide additional coding efficiency, greater flexibility, and throughput at high bit depths/rates. Improved lossless, nearlossless, and very high bit-rate coding is also part of the RExt scope. This paper presents the technical aspects of the HEVC Range Extensions, including a discussion of RExt profiles, tools, applications, and provides experimental results for a performance comparison with previous relevant coding technology. When compared to the High 4:4:4 Predictive Profile of H.264/AVC, the corresponding HEVC 4:4:4 RExt profile provides up to ∼25%, ∼32%, and ∼36% average bit-rate reduction at the same PSNR quality level for intra, random access, and low delay configurations, respectively.Index Terms-HEVC, H.265, MPEG-H, Range Extensions (RExt), video compression, standards • Content production in a digital video broadcasting delivery chain: This application commonly employs 4:2:2 chroma format at 10 bits per sample.
