Rec2020
   HOME

TheInfoList



OR:

ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of
ultra-high-definition television Ultra-high-definition television (also known as Ultra HD television, Ultra HD, UHDTV, UHD and Super Hi-Vision) today includes 4K UHD and 8K UHD, which are two digital video formats with an aspect ratio of 16:9. These were first proposed by ...
(UHDTV) with
standard dynamic range Standard-dynamic-range (SDR) video is a video technology which represents light intensity based on the brightness, contrast and color characteristics and limitations of a cathode ray tube (CRT) display. SDR video is able to represent a video or p ...
(SDR) and wide color gamut (WCG), including
picture resolution Image resolution is the detail an image holds. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how cl ...
s,
frame rate Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images (frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also be ca ...
s with
progressive scan Progressive scanning (alternatively referred to as noninterlaced scanning) is a format of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video used ...
, bit depths, color primaries, RGB and luma-chroma color representations, chroma subsamplings, and an
opto-electronic transfer function This article is about the transfer functions used in pictures and videos and describing the relationship between electrical signal, scene light and displayed light. Definition The opto-electronic transfer function (OETF) is the transfer function ...
. The first version of Rec. 2020 was posted on the
International Telecommunication Union The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
(ITU) website on August 23, 2012, and two further editions have been published since then. Rec. 2020 is extended for high-dynamic-range (HDR) by Rec. 2100, which uses the same color primaries as Rec. 2020.


Technical details


Resolution

Rec. 2020 defines two standard image formats of 3840 × 2160 ("4K") and 7680 × 4320 ("8K"). These both have an aspect ratio of 16:9 and use square
pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smal ...
s.


Frame rate

Rec. 2020 specifies the following frame rates: 120p, 119.88p, 100p, 60p, 59.94p, 50p, 30p, 29.97p, 25p, 24p, 23.976p. Only
progressive scan Progressive scanning (alternatively referred to as noninterlaced scanning) is a format of displaying, storing, or transmitting moving images in which all the lines of each frame are drawn in sequence. This is in contrast to interlaced video used ...
frame rates are allowed.


Digital representation

Rec. 2020 defines a bit depth of either 10 bits per sample or 12 bits per sample. 10 bits per sample Rec. 2020 uses video levels where the black level is defined as code 64 and the nominal peak is defined as code 940. Codes 0–3 and 1,020–1,023 are used for the timing reference. Codes 4 through 63 provide video data below the black level while codes 941 through 1,019 provide video data above the nominal peak. 12 bits per sample Rec. 2020 uses video levels where the black level is defined as code 256 and the nominal peak is defined as code 3760. Codes 0–15 and 4,080–4,095 are used for the timing reference. Codes 16 through 255 provide video data below the black level while codes 3,761 through 4,079 provide video data above the nominal peak.


System colorimetry

The Rec. 2020 (UHDTV/UHD-1/UHD-2) color space can reproduce colors that cannot be shown with the
Rec. 709 Rec. 709, also known as Rec.709, BT.709, and ITU 709, is a standard developed by ITU-R for image encoding and signal characteristics of high-definition television. The most recent version is BT.709-6 released in 2015. BT.709-6 defines the P ...
(HDTV) color space. The RGB primaries used by Rec. 2020 are equivalent to monochromatic light sources on the CIE 1931 spectral locus. The
wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...
of the Rec. 2020 primary colors is 630 nm for the red primary color, 532 nm for the green primary color, and 467 nm for the blue primary color. In coverage of the CIE 1931 color space, the Rec. 2020 color space covers 75.8%, the DCI-P3 digital cinema color space covers 53.6%, the Adobe RGB color space covers 52.1%, and the
Rec. 709 Rec. 709, also known as Rec.709, BT.709, and ITU 709, is a standard developed by ITU-R for image encoding and signal characteristics of high-definition television. The most recent version is BT.709-6 released in 2015. BT.709-6 defines the P ...
color space covers 35.9%. During the development of the Rec. 2020 color space it was decided that it would use real colors, instead of
imaginary color Impossible colors are colors that do not appear in ordinary visual functioning. Different color theories suggest different hypothetical colors that humans are incapable of perceiving for one reason or another, and fictional colors are rou ...
s, so that it would be possible to show the Rec. 2020 color space on a display without the need for conversion circuitry. Since a larger color space increases the difference between colors, an increase of 1 bit per sample is needed for Rec. 2020 to equal or exceed the color precision of Rec. 709. The NHK measured
contrast sensitivity Contrast is the contradiction in luminance or colour that makes an object (or its representation in an image or display) distinguishable. In visual perception of the real world, contrast is determined by the difference in the colour and brightn ...
for the Rec. 2020 color space using Barten's equation which had previously been used to determine the bit depth for digital cinema. 11 bits per sample for the Rec. 2020 color space is below the visual modulation threshold, the ability to discern a one-value difference in
luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...
, for the entire luminance range. The NHK is planning for their UHDTV system, Super Hi-Vision, to use 12 bits per sample RGB.


Transfer characteristics

Rec. 2020 defines a
nonlinear In mathematics and science, a nonlinear system is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathematicians, and many other ...
transfer function for
gamma correction Gamma correction or gamma is a nonlinear operation used to encode and decode luminance or tristimulus values in video or still image systems. Gamma correction is, in the simplest cases, defined by the following power-law expression: : V_\text = ...
that is the same nonlinear transfer function that is used by Rec. 709, except that its parameters are (for 12 bit only) given with higher precision: E^\prime=\begin 4.5E & 0 \le E < \beta\,\!\\ \alpha\,\!E^ - (\alpha\,\! - 1) & \beta\,\! \le E \le 1 \end *where ''E'' is the signal proportional to camera-input light intensity and ''E′'' is the corresponding nonlinear signal *where ''α'' = 1 + 5.5 * ''β'' ≈ 1.09929682680944 and ''β'' ≈ 0.018053968510807 (values chosen to achieve a continuous function with a continuous first derivative) The standard says that for practical purposes, the following values of ''α'' and ''β'' can be used: * ''α'' = 1.099 and ''β'' = 0.018 for 10 bits per sample system (the values given in Rec. 709) * ''α ''= 1.0993 and ''β'' = 0.0181 for 12 bits per sample system While the Rec. 2020 transfer function can be used for encoding, it is expected that most productions will use a reference monitor that has an appearance of using equivalent of gamma 2.4 transfer function as defined in
ITU-R BT.1886 ITU-R BT.1886 is the reference EOTF of Standard-dynamic-range video, SDR-TV. It is a Gamma correction, gamma 2.4 transfer function (a power law with a 2.4 exponent) considered as a satisfactory approximation of the response characteristic of Cat ...
and that the reference monitor will be evaluated under viewing conditions as defined in Rec. ITU-R BT.2035.


RGB and luma-chroma formats

Rec. 2020 allows for RGB and luma-chroma signal formats with 4:4:4 full-resolution sampling and luma-chroma signal formats with 4:2:2 and 4:2:0 chroma subsampling. It supports two types of luma-chroma signals, called YCbCr and YcCbcCrc. YCbCr may be used when the top priority is compatibility with existing
SDTV Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing sp ...
and
HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the g ...
operating practices. The luma (Y′) signal for YCbCr is calculated as the weighted average Y′ = KR⋅R′ + KG⋅G′ + KB⋅B′, using the gamma-corrected RGB values (denoted R′G′B′) and the weighting coefficients KR = 0.2627, KG = 1−KR−KB = 0.678 and KB = 0.0593. As in similar schemes, the chroma components in YCbCr are calculated as C′B = 0.5⋅(B′−Y′)/(1−KB) = (B'−Y′)/1.8814 and C′R = 0.5⋅(R′−Y′)/(1−KR) = (R′−Y′)/1.4746, and for digital representation the Y′, C′B, and C′R signals are scaled, offset by constants, and rounded to integers. The YcCbcCrc scheme is a "constant luminance" luma-chroma representation. YcCbcCrc may be used when the top priority is the most accurate retention of luminance information. The luma component in YcCbcCrc is calculated using the same coefficient values as for YCbCr, but it is calculated from linear RGB and then gamma corrected, rather than being calculated from gamma-corrected R′G′B′ and is done as follows: Y′ = (KR⋅R + KG⋅G + KB⋅B)′. The chroma components in YcCbcCrc are calculated from the Y′, B′, and R′ signals with equations that depend on the range of values of B′−Y′ and R′−Y′.


Color management

Just like standard definition content, that uses
SMPTE C The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
or NTSC 1953, BT.2020 primaries should be color managed to primaries of display. That is different from changing YCbCr matrix. HD content is color managed to BT.709 primaries on linear values. BT.2020 and BT.2100 are usually color managed to P3-D65. The reference color bars for BT.2020 are ARIB STD-B66.


Implementations

HDMI 2.0 High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, t ...
supports the Rec. 2020 color space. HDMI 2.0 can transmit 12 bits per sample RGB at a resolution of 2160p and a frame rate of 24/25/30 fps or it can transmit 12 bits per sample 4:2:2/4:2:0 YCbCr at a resolution of 2160p and a frame rate of 50/60 fps. The Rec. 2020 color space is supported by H.264/MPEG-4 AVC and H.265/
High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compar ...
(HEVC). The Main 10 profile in HEVC was added based on proposal JCTVC-K0109 which proposed that a 10-bit profile be added to HEVC for consumer applications. The proposal stated that this was to allow for improved video quality and to support the Rec. 2020 color space that will be used by UHDTV. On September 11, 2013, ViXS Systems announced the XCode 6400 SoC which supports
4K resolution 4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K Ultra-high-definitio ...
at 60 fps, the Main 10 profile of HEVC, and the Rec. 2020 color space.


2014

On May 22, 2014, Nanosys announced that using a
quantum dot Quantum dots (QDs) are semiconductor particles a few nanometres in size, having light, optical and electronics, electronic properties that differ from those of larger particles as a result of quantum mechanics. They are a central topic in nanote ...
enhancement film (QDEF) a current LCD TV was modified so that it could cover 91% of the Rec. 2020 color space. Nanosys engineers believe that with improved LCD color filters it is possible to make a LCD that covers 97% of the Rec. 2020 color space. On September 4, 2014, Canon Inc. released a firmware upgrade, that added support for the Rec. 2020 color space, to their EOS C500 and EOS C500 PL camera models and their DP-V3010 4K display. On September 5, 2014, the
Blu-ray Disc Association The Blu-ray Disc Association (BDA) is the industry consortium that develops and licenses Blu-ray Disc technology and is responsible for establishing format standards and promoting business opportunities for Blu-ray Disc. The BDA is divided into ...
revealed that the future 4K
Blu-ray Disc The Blu-ray Disc (BD), often known simply as Blu-ray, is a Digital media, digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and c ...
format will support 4K UHD (3840x2160 resolution) video at frame rates up to 60 frames per second. The standard will encode videos under the
High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compar ...
standard. 4K Blu-ray Discs support both a higher color precision by increasing the
color depth Color depth or colour depth (see spelling differences), also known as bit depth, is either the number of bits used to indicate the color of a single pixel, or the number of bits used for each color component of a single pixel. When referring to ...
to 10 bits per color, and a greater color gamut by using the Rec. 2020 color space. The 4K-Blu-ray specification allows for three disc sizes, each with their own data rate: 50 GB with 82 Mbit/s, 66 GB with 108 Mbit/s, and 100 GB with 128 Mbit/s. The first Ultra HD Blu-ray titles were officially released from four studios on March 1, 2016. On November 6, 2014,
Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...
added support for the Rec. 2020 color space to
VP9 VP9 is an open and royalty-free video coding format developed by Google. VP9 is the successor to VP8 and competes mainly with MPEG's High Efficiency Video Coding (HEVC/H.265). At first, VP9 was mainly used on Google's video platform YouTube. ...
. On November 7, 2014, DivX developers announced that DivX265 version 1.4.21 has added support for the Main 10 profile of HEVC and the Rec. 2020 color space. On December 22, 2014, Avid Technology released an update for Media Composer that added support for 4K resolution, the Rec. 2020 color space, and a bit rate of up to 3,730 Mbit/s with the
DNxHD codec Avid DNxHD ("Digital Nonlinear Extensible High Definition") is a lossy high-definition video post-production codec developed by Avid for multi-generation compositing with reduced storage and bandwidth requirements. It is an implementation of SMPTE ...
.


2015

On January 6, 2015, the MHL Consortium announced the release of the
superMHL Mobile High-Definition Link (MHL) is an Technical standard, industry standard for a mobile audio/video interface that allows the connection of smartphones, tablets, and other portable consumer electronics devices to high-definition televisions (H ...
specification which will support
8K resolution 8K resolution refers to an image or display resolution with a width of approximately 8,000 pixels. 8K UHD () is the highest resolution defined in the Rec. 2020 (UHDTV) standard. 8K display resolution is the successor to 4K resolution. TV manuf ...
at 120 fps, 48-bit video, the Rec. 2020 color space, high dynamic range support, a 32-pin reversible superMHL connector, and power charging of up to 40 watts. On January 7, 2015,
Ateme Ateme S.A. is a multinational company that specializes in video delivery, namely software for video compression based on H.265 / HEVC standards; MPEG4; MPEG2 encoding / decoding solutions for contribution links, multi-screen live streaming, OTT ...
added support for the Rec. 2020 color space to their TITAN File video platform. On March 18, 2015,
Arri The Arri Group () is a German manufacturer of motion picture film equipment. Based in Munich, the company was founded in 1917. It produces professional motion picture cameras, lenses, lighting and post-production equipment. Hermann Simon menti ...
announced the SXT line of Arri Alexa cameras which will support
Apple ProRes Apple ProRes is a high quality, "visually lossless" lossy video compression format developed by Apple Inc. for use in post-production that supports video resolution up to 8K. It is the successor of the Apple Intermediate Codec and was introduced ...
recording at 4K resolution and the Rec. 2020 color space. On April 8, 2015, Canon Inc. announced the DP-V2410 4K display and EOS C300 Mark II camera with support for the Rec. 2020 color space. On May 26, 2015, the NHK announced a 4K LCD with a
laser diode file:Laser diode chip.jpg, The laser diode chip removed and placed on the eye of a needle for scale A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a di ...
backlight that covers 98% of the Rec. 2020 color space. Using a laser allows for generating almost monochromatic light. The NHK stated that at the time it was announced this 4K LCD has the widest color gamut of any display in the world. On June 17, 2015, Digital Projection International presented a 4K LED projector with support for the Rec. 2020 color space.


2016

On January 4, 2016, the UHD Alliance announced their specifications for Ultra HD Premium which includes support for the Rec. 2020 color space. On January 27, 2016, VESA announced that
DisplayPort DisplayPort (DP) is a digital display interface developed by a consortium of PC and chip manufacturers and standardized by the Video Electronics Standards Association (VESA). It is primarily used to connect a video source to a display device su ...
version 1.4 will support the Rec. 2020 color space. On April 17, 2016,
Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
presented a 4K OLED display with the support of Rec. 2020 color space. On April 18, 2016, the
Ultra HD Forum Ultra HD Forum is an organization whose goal is to help solve the real world hurdles in deploying Ultra HD video and thus to help promote UHD deployment. The Ultra HD Forum will help navigate amongst the standards related to high dynamic range (H ...
announced industry guidelines for UHD Phase A which includes support for the Rec. 2020 color space.


2017

At SID display week 2017, AUO displayed a 5" foldable 720p HD AMOLED display able to display 95% of the Rec. 2020 colorspace. Although 720p is not specified by Rec. 2020, the color space coverage is of note. The Ultra HD Forum guidelines for
UHD Phase A Ultra HD Forum is an organization whose goal is to help solve the real world hurdles in deploying Ultra HD video and thus to help promote UHD deployment. The Ultra HD Forum will help navigate amongst the standards related to high dynamic range (H ...
include support for SDR formats with 10 bits of color bit depth based on both Rec. 709 and Rec. 2020 color gamuts and also both the HDR10 and HLG formats of Rec. 2100, which are supposed to start by 2017.


2018

At SID display week 2018, various companies showcased displays that are able to cover over 90% of the Rec.2020 color space. JDI showcased an improvement of their 17.3" LCD 8k broadcast monitor that is powered by an RGB laser backlight system. This allows the display to reproduce 97% of the Rec. 2020 color space.


Rec. 2100

Rec. 2100 is an ITU-R Recommendation released in July 2016 that defines
high dynamic range High dynamic range (HDR) is a dynamic range higher than usual, synonyms are wide dynamic range, extended dynamic range, expanded dynamic range. The term is often used in discussing the dynamic range of various signals such as images, videos, au ...
(HDR) formats for both HDTV 1080p and 4K/8K UHDTV resolutions. These formats use the same color primaries as Rec. 2020, but with different transfer functions for HDR use. Rec. 2100 does not support the YcCbcCrc scheme of Rec. 2020.


See also

*
UHDTV Ultra-high-definition television (also known as Ultra HD television, Ultra HD, UHDTV, UHD and Super Hi-Vision) today includes 4K UHD and 8K UHD, which are two digital video formats with an aspect ratio of 16:9. These were first proposed by ...
– Digital video formats with resolutions of 4K (3840 × 2160) and 8K (7680 × 4320) *
High Efficiency Video Coding High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In compar ...
(HEVC) – Video standard that supports 4K/8K UHDTV and resolutions up to 8192 × 4320 *
Rec. 709 Rec. 709, also known as Rec.709, BT.709, and ITU 709, is a standard developed by ITU-R for image encoding and signal characteristics of high-definition television. The most recent version is BT.709-6 released in 2015. BT.709-6 defines the P ...
– ITU-R Recommendation for HDTV *
Rec. 601 ITU-R Recommendation BT.601, more commonly known by the abbreviations Rec. 601 or BT.601 (or its former name CCIR 601) is a standard originally issued in 1982 by the CCIR (an organization, which has since been renamed as the Internatio ...
– ITU-R Recommendation for SDTV *
Rec. 2100 ITU-R Recommendation BT.2100, more commonly known by the abbreviations Rec. 2100 or BT.2100, introduced high-dynamic-range television (HDR-TV) by recommending the use of the perceptual quantizer (PQ) or hybrid log–gamma (HLG) transfer func ...
– ITU-R Recommendation for HDR-TV (with FHD and UHD resolution)


References


External links


ITU-R Recommendation BT.2020
{{Color space Color space Film and video technology ITU-R recommendations Telecommunications-related introductions in 2012 Audiovisual introductions in 2012 Television transmission standards Ultra-high-definition television