The ITU has announced – and confirmed – the REC-2100 enhanced standard, and which builds on the ‘REC-2020’ standard for high-dynamic range (HDR) broadcasting.
“[HDR] represents a major advance in television broadcasting. HDR brings an incredible feeling of realism, building further on the superior colour fidelity of ITU’s Ultra-High Definition Television Recommendation BT.2020. ITU’s Radiocommunication Sector (ITU-R) has developed the standard – or Recommendation – in collaboration with experts from the television industry, broadcasting organisations and regulatory institutions in its Study Group 6,” said the ITU.
“REC-2100 brings a further boost to television images, giving viewers an enhanced visual experience with added realism. The HDR-TV Recommendation allows TV programmes to take full advantage of the new and much brighter display technologies. HDR-TV can make outdoor sunlit scenes appear brighter and more natural, adding highlights and sparkle. It enhances dimly lit interior and night scenes, revealing more detail in darker areas, giving TV producers the ability to reveal texture and subtle colours that are usually lost with existing Standard Dynamic Range TV.”
The HDR-TV Recommendation details two options for producing High Dynamic Range TV images. The Perceptual Quantization (PQ) specification achieves a very wide range of brightness levels using a transfer function that is finely tuned to match the human visual system and the Hybrid Log-Gamma (HLG) specification [backed by the BBC and NHK of Japan] which offers a degree of compatibility with legacy displays by more closely matching the previously established television transfer curves. The Recommendation also outlines a simple conversion process between the two HDR-TV options.
“The ITU-R Recommendation BT.2100 also allows TV producers to choose from three levels of detail or resolution: HDTV (1920 by 1080), and UHDTV ‘4K’ (3840 by 2160) and ‘8K’ (7680 by 4320) – all of which use the progressive imaging system with extended colour gamut and range of frame-rates in ITU’s UHDTV Recommendation BT.2020.”
“This Recommendation is the culmination of three years of intensive work by dedicated image experts from around the world. HDR images are stunning and this is another major step forward in television quality,” said Andy Quested, Chairman of ITU-R Working Party 6C (WP 6C), which developed the new standard. “Programme makers today need a much wider range of options in order to meet the expectations of the different platforms they must supply, and this need for flexibility is catered for within the framework of a stable ITU-R Recommendation.”