On 05 July 2016, the ITU published its recommendation, BT.2100, on High Dynamic Range (HDR)-TV. This document represents the outcome of several years of studies and evaluations on recommended systems with the aim to provide viewers and broadcasters with the best possible HDR experience.
The HDR-TV Recommendation details two options for producing HDR TV images. The PQ specification offers a very wide range of brightness levels for a given bit depth using a non-linear transfer function that is finely tuned to match the human visual system. The HLG specification offers a degree of compatibility with legacy displays by more closely matching the previously established television transfer curves. The Recommendation also includes a conversion mechanism between the two formats.
The HDR recommendation specifies three (3) master production formats (HDTV 1080p, 4k and 8k) with downscaling possibilities. Nonetheless, in order to accommodate the new higher range of brightness, a minimum of 10 bits are required for signal representation.
Simon Fell, Director of Technology and Innovation at EBU said “The EBU would like to thank Yukihiro Nishida (Chairman of ITU-R Study Group 6) and Andy Quested (Chairman of ITU-R Working Party 6C) for this recommendation, we think this is a major step for the adoption of higher dynamic range in TV systems in the near future. This is something that the viewers and industry will highly benefit from.”