High-dynamic-range television (HDR or HDR-TV) is a technology that improves the quality of display signals. It is contrasted with the retroactively-named
standard dynamic range (SDR). HDR changes the way the luminance and colors of videos and images are represented in the signal, and allows brighter and more detailed highlight representation, darker and more-detailed shadows, and a wider array of more intense colors.
HDR allows compatible displays to receive a higher quality image source. It does not improve a display's intrinsic properties (brightness, contrast, and color capabilities). Not all HDR displays have the same capabilities, and HDR content will look different depending on the display used.
HDR-TV was first used in 2014 to enhance videos,
and it is now also available for still pictures.
HDR-TV is a part of
HDR imaging
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 ...
, an end-to-end process of increasing the dynamic range of images and videos from their capture and creation, to their storage, distribution and display. HDR-TV also improves
color gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
, as
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 ...
and all common HDR formats require HDR to be delivered with
wide color gamuts (WCG).
Description
Before HDR, improvements in display fidelity were typically achieved by increasing the pixel quantity, density (resolution) and the display's frame rate. By contrast, HDR improves the perceived fidelity of the existing individual pixels. Standard dynamic range (SDR) is still based on and limited by the characteristics of older
cathode ray tubes
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms (oscilloscope), pictur ...
(CRT), despite the huge advances in screen and display technologies since CRT's obsolescence.
SDR formats are able to represent a maximum
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 ...
level of around 100
nits
The National Institutes of Technology (NITs) are the central government-owned-public technical institutes under the ownership of Ministry of Education, Government of India. They are governed by the National Institutes of Technology, Science ...
. For HDR, this number increases to around 1,000–10,000 nits.
HDR can represent darker black levels
and more saturated colors.
The most common SDR formats are limited to 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 ...
/
sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ( ...
gamut, while common HDR formats use Rec. 2100, which is a wide color gamut (WCG).
In practice, HDR is not always used at its limits. HDR contents are often limited to a peak brightness of 1,000 or 4,000 nits and
P3-D65 colors, even if they are stored in formats capable of more.
Content creators can choose to what extent they make use of HDR capabilities. They can constrain themselves to the limits of SDR even if the content is delivered in an HDR format.
The benefits of HDR depend on the display capabilities, which vary. No current display is able to reproduce the maximal range of brightness and colors that can be represented in HDR formats.
Benefits
The highlights—the brightest parts of an image—can be brighter, more colorful, and more detailed.
The larger capacity for brightness can be used to increase the brightness of small areas without increasing the overall image's brightness, resulting in, for example, bright reflections from shiny objects, bright stars in a dark night scene, and bright and colorful light-emissive objects (e.g. fire, and sunset).
The shadows or lowlights—the darkest parts of an image—can be darker and more detailed.
The colorful parts of the image can be even more colorful if a WCG is used.
The color dynamism and wider range of colors frequently attributed to HDR video is actually a consequence of a WCG. This has become a point of significant confusion among consumers, whereby HDR and WCG are either confused for each other or treated as interchangeable. While HDR displays typically have WCGs and displays with WCGs are usually capable of HDR, one does not imply the other; there are SDR displays with WCGs. Some HDR standards specify WCG as a prerequisite of compliance. Regardless, when a WCG is available on an HDR display, the image as a whole can be more colorful due to the wider range of colors.
More subjective, practical benefits of HDR video include more realistic luminance variation between scenes (such as sunlit, indoor, and night scenes), better surface material identification, and better in-depth perception, even with 2D imagery.
Preservation of content creator intent
When a display’s capabilities are insufficient to reproduce all the brightness, contrast and colors that are represented in the HDR content, the image needs to be adjusted to fit the display’s capabilities. Some HDR formats (such as Dolby Vision and HDR10+) allow the content creator to choose how the adjustment will be done.
Other HDR formats (such as HDR10 and
hybrid log–gamma
The hybrid log–gamma (HLG) transfer function is a transfer function jointly developed by the BBC and NHK for high dynamic range (HDR) display. It's backward compatible with the transfer function of SDR (the gamma curve). It was approved as ARIB S ...
(HLG)) do not offer this possibility, so the content creator's intents are not ensured to be preserved on lower capable displays.
For optimal quality, standards require video to be created and viewed in a relatively dark environment.
Dolby Vision IQ and HDR10+ Adaptive adjust the content according to the ambient light.
Formats
Since 2014, multiple HDR formats have emerged including
HDR10
HDR10 Media Profile, more commonly known as HDR10, is an open high-dynamic-range video (HDR) standard announced on 27 August 2015 by the Consumer Technology Association. It is the most widespread of the HDR formats.
HDR10 is not backward compati ...
,
HDR10+
HDR10+ is a high dynamic range (HDR) video technology that adds dynamic metadata to HDR10 source files. The dynamic metadata are used to adjust and optimize each frame of the HDR video to the consumer display's capabilities in a way based on the ...
,
Dolby Vision
Dolby Vision is a set of technologies developed by Dolby Laboratories for high dynamic range (HDR) video. It covers content creation, distribution, and playback. It includes dynamic metadata that are used to adjust and optimize each frame of the ...
, and
HLG.
Some formats are royalty-free and others require a license. The formats vary in their capabilities.
Dolby Vision and HDR10+ include dynamic metadata while HDR10 and HLG do not.
The dynamic metadata are used to improve image quality on limited displays that are not capable of reproducing an HDR video to its fullest intended extent. Dynamic metadata allows content creators to control and choose the way the image is adjusted.
HDR10
The HDR10 Media Profile, more commonly known as HDR10, is an open HDR standard announced on 27 August 2015 by the
Consumer Technology Association
The Consumer Technology Association (CTA) is a standard and trade organization representing 1,376 consumer technology companies in the United States. CTA works to influence public policy, holds events such as the Consumer Electronics Show (CES ...
.
It is the most widespread of the HDR formats,
and is not backward compatible with SDR displays. It is technically limited to a maximum peak brightness of 10,000 nits; however, HDR10 content is commonly mastered with a peak brightness between 1000 and 4000 nits.
HDR10 lacks dynamic metadata.
On HDR10 displays that have lower color volume than the HDR10 content (such as lower peak brightness capability), the HDR10 metadata provides information to help the display adjust to the video.
The metadata is static and constant with respect to each individual video, and does not inform the display exactly how the content should be adjusted. The interaction between display capabilities, video metadata, and the ultimate output (i.e. the presentation of the video) is mediated by the display, with the result that the original producer's intent may not be preserved.
Dolby Vision
![Dolby Vision 2021 logo](https://upload.wikimedia.org/wikipedia/commons/0/03/Dolby_Vision_2021_logo.svg)
Dolby Vision is an end-to-end ecosystem for HDR video, and covers content creation, distribution, and playback.
It uses dynamic metadata and is capable of representing luminance levels of up to 10,000 nits.
Dolby Vision certification requires displays for content creators to have a peak luminance of at least 1,000 nits.
HDR10+
![HDR10+ Logo](https://upload.wikimedia.org/wikipedia/commons/2/22/HDR10%2B_Logo.png)
HDR10+, also known as HDR10 Plus, is an HDR video format announced on 20 April 2017.
It is the same as HDR10 but with the addition of a system of dynamic metadata developed by Samsung.
It is free to use for content creators and has a maximum $10,000 annual license for some manufacturers. It has been positioned as an alternative to Dolby Vision without the same expenses.
HLG
HLG format is an HDR format that can be used for video and still images.
It uses the
HLG transfer function, Rec. 2020 color primaries, and a
bit depth of 10 bits.
The format is backwards compatible with SDR
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 ...
, but not with older SDR displays that do not implement the Rec. 2020 color standards.
It does not use metadata and is royalty-free.
PQ10 (PQ format)
PQ10, sometimes referred to as the PQ format, is an HDR format that can be used for video and still images.
It is the same as the HDR10 format without any metadata.
It uses the
perceptual quantizer
The perceptual quantizer (PQ), published by SMPTE as SMPTE ST 2084, is a transfer function that allows for HDR display by replacing the gamma curve used in SDR. It is capable of representing luminance level up to 10000 cd/m2 (nits) and down to ...
(PQ) transfer function, Rec. 2020 color primaries and a bit depth of 10-bits.
HDR Vivid
HDR Vivid is an HDR format developed by the China Ultra HD Video Alliance (CUVA) and released in March 2021. It uses dynamic metadata standardized in CUVA 005-2020.
Other formats
* Technicolor Advanced HDR: An HDR format which aims to be backwards compatible with SDR.
there is no commercial content available in this format.
* SL-HDR1 (Single-Layer HDR system Part 1) is an HDR standard that was jointly developed by
STMicroelectronics
STMicroelectronics N.V. commonly referred as ST or STMicro is a Dutch multinational corporation and technology company of French-Italian origin headquartered in Plan-les-Ouates near Geneva, Switzerland and listed on the French stock market. ST ...
,
Philips International B.V., and
Technicolor R&D France.
It was standardised as ETSI TS 103 433 in August 2016.
SL-HDR1 provides direct backwards compatibility by using static (SMPTE ST 2086) and dynamic metadata (using SMPTE ST 2094-20 Philips and 2094-30 Technicolor formats) to reconstruct a HDR signal from an SDR video stream that can be delivered using existing SDR distribution networks and services. SL-HDR1 allows for HDR rendering on HDR devices and SDR rendering on SDR devices using a single-layer video stream.
The HDR reconstruction metadata can be added either to
HEVC
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 compari ...
or
AVC
AVC may refer to:
Organizations
* Asian Volleyball Confederation, the continental governing body for the sport of volleyball in Asia
* Advanced Video Communications, owner of Stickam
* ¡Alfaro Vive, Carajo!, a defunct left-wing group in Ecuador
...
using a supplemental enhancement information (SEI) message.
Version 1.3.1 was published in March 2020.
*SL-HDR2
*SL-HDR3
Comparison of HDR formats
Notes
Displays
TV sets with enhanced dynamic range and upscaling of existing SDR/LDR video/broadcast content with reverse
tone mapping
Tone mapping is a technique used in image processing and computer graphics to map one set of colors to another to approximate the appearance of high-dynamic-range images in a medium that has a more limited dynamic range. Print-outs, CRT or L ...
have been anticipated since early 2000s. In 2016, HDR conversion of SDR video was released to market as
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
's ''HDR+'' (in
LCD TV
Liquid-crystal-display televisions (LCD TVs) are television sets that use liquid-crystal displays to produce images. They are, by far, the most widely produced and sold television display type. LCD TVs are thin and light, but have some disadvantag ...
sets)
and Technicolor SA's HDR Intelligent Tone Management.
As of 2018, high-end consumer-grade HDR displays can achieve 1,000 cd/m
2 of luminance, at least for a short duration or over a small portion of the screen, compared to 250-300 cd/m
2 for a typical SDR display.
Video interfaces that support at least one HDR Format include
HDMI
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, ...
2.0a, which was released in April 2015 and
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 ...
1.4, which was released in March 2016.
On 12 December 2016, HDMI announced that Hybrid Log-Gamma (HLG) support had been added to the HDMI 2.0b standard.
HDMI 2.1
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, ...
was officially announced on 4 January 2017, and added support for Dynamic HDR, which is dynamic metadata that supports changes scene-by-scene or frame-by-frame.
Compatibility
As of 2020, no display is capable of rendering the full range of brightness and color of HDR formats.
A display is called an ''HDR display'' if it can accept HDR content and map them to its display characteristics,
so the HDR logo only provides information about content compatibility and not display capability.
Displays that uses global dimming, such as most
edge-lit LED displays, cannot display the advanced contrast of HDR content. Some displays implement local dimming technologies, such as
OLED
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...
and full-array
LED-backlighting, to more properly display advanced contrast.
Certifications
VESA DisplayHDR
The DisplayHDR standard from
VESA
VESA (), formally known as Video Electronics Standards Association, is an American technical standards organization for computer display standards. The organization was incorporated in California in July 1989To retrieve the information, searc ...
is an attempt to make the differences in HDR specifications easier to understand for consumers, with standards mainly used in computer monitors and laptops. VESA defines a set of HDR levels; all of them must support HDR10, but not all are required to support 10-bit displays. DisplayHDR is not an HDR format, but a tool to verify HDR formats and their performance on a given monitor. The most recent standard is DisplayHDR 1400, which was introduced in September 2019, with monitors supporting it released in 2020. DisplayHDR 1000 and DisplayHDR 1400 are primarily used in professional work like video editing. Monitors with DisplayHDR 500 or DisplayHDR 600 certification provide a noticeable improvement over SDR displays, and are more often used for general computing and gaming.
Other certifications
UHD Alliance certifications:
* Ultra HD Premium
* Mobile HDR Premium: for mobile devices.
Technical details
HDR is mainly achieved by the use of PQ or HLG
transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a function (mathematics), mathematical function that mathematical model, theoretically models the system's output for ...
.
WCGs are also commonly used along HDR up to Rec. 2020
color primaries.
A bit depth of 10 or 12 bits is used to not see
banding across the extended brightness range. In some cases, additional
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the descriptive ...
are used to handle the variety in displays
brightness
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, ...
,
contrast and colors. HDR video is defined in
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 ...
.
Color space
ITU-R Rec. 2100
Rec. 2100 is a technical recommendation by ITU-R for production and distribution of HDR content using 1080p or UHD resolution, 10-bit or 12-bit color, HLG or PQ transfer functions, full or limited range, the Rec. 2020 wide color gamut and ''
YCBCR'' or
''ICTCP'' as
color space
A color space is a specific organization of colors. In combination with color profiling supported by various physical devices, it supports reproducible representations of colorwhether such representation entails an analog or a digital represent ...
.
Transfer function
SDR uses a
gamma curve
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 = ...
transfer function that is based on CRT characteristics, and is used to represent luminance levels up to around 100 nits.
HDR uses newly developed PQ or HLG transfer functions instead of the traditional gamma curve.
If the gamma curve would have been extended to 10,000 nits, it would have required a bit-depth of 15 bits to avoid banding.
HDR transfer functions:
* PQ, or SMPTE ST 2084,
is a
transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a function (mathematics), mathematical function that mathematical model, theoretically models the system's output for ...
developed for HDR that is able to represent luminance level up to 10,000
cd/m2.
It is the basis of HDR video formats (such as Dolby Vision,
HDR10
HDR10 Media Profile, more commonly known as HDR10, is an open high-dynamic-range video (HDR) standard announced on 27 August 2015 by the Consumer Technology Association. It is the most widespread of the HDR formats.
HDR10 is not backward compati ...
and
HDR10+
HDR10+ is a high dynamic range (HDR) video technology that adds dynamic metadata to HDR10 source files. The dynamic metadata are used to adjust and optimize each frame of the HDR video to the consumer display's capabilities in a way based on the ...
) and is also used for HDR still picture formats.
PQ is not
backward compatible
Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially i ...
with
SDR. PQ encoded in 12 bits does not produce visible
banding.
* HLG is a transfer function developed by the
NHK
, also known as NHK, is a Japanese public broadcaster. NHK, which has always been known by this romanized initialism in Japanese, is a statutory corporation funded by viewers' payments of a television license fee.
NHK operates two terrestri ...
and
BBC #REDIRECT BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board ex ...
.
It is backward compatible with SDR's gamma curve, and is the basis of an HDR format known as HLG.
The HLG transfer function is also used by other video formats such Dolby Vision profile 8.4 and for HDR still picture formats.
HLG is
royalty-free
Royalty-free (RF) material subject to copyright or other intellectual property rights may be used without the need to pay royalties or license fees for each use, per each copy or volume sold or some time period of use or sales.
Computer standard ...
.
Color primaries
SDR for HD video uses a system chromaticity (
chromaticity
Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called ...
of
color primaries and
white point
A white point (often referred to as reference white or target white in technical documents) is a set of tristimulus values or chromaticity coordinates that serve to define the color "white" in image capture, encoding, or reproduction. Depending on ...
) specified in
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 ...
(same as
sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ( ...
).
SDR for SD used many different primaries, as said in BT.601, SMPTE 170M and BT.470.
HDR is commonly associated to a WCG (a system
chromaticity
Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called ...
wider than
BT.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 ...
).
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 ...
(HDR-TV) uses the same system chromaticity that is used in Rec. 2020 (UHDTV).
HDR formats such as HDR10, HDR10+, Dolby Vision and HLG also use Rec. 2020 chromaticities.
HDR contents are commonly graded on a P3-D65 display.
File:CIExy1931 Rec 709.svg, Rec.709 and sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ( ...
(SDR)
File:DCI-P3 D65.svg, P3-D65 (common HDR contents)
File:CIExy1931 Rec 2020.svg, Rec.2020
ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture ...
and Rec.2100 (HDR technical limit)
Bit depth
Because of the increased
dynamic range
Dynamic range (abbreviated DR, DNR, or DYR) is the ratio between the largest and smallest values that a certain quantity can assume. It is often used in the context of signals, like sound and light. It is measured either as a ratio or as a base-1 ...
, HDR contents need to use more bit depth than SDR to avoid banding. While SDR uses a bit depth of 8 or 10 bits,
HDR uses 10 or 12 bits,
which when combined with the use of more efficient transfer function like PQ or HLG, is enough to avoid banding.
Matrix coefficients
Rec. 2100 specifies the use of the
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
, YCbCr or IC
TC
P signal formats for HDR-TV.
IC
TC
P is a color representation designed by Dolby for HDR and wide color gamut (WCG) and standardized in
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 ...
.
IPTPQc2 with reshaping is a proprietary format by Dolby and is similar to IC
TC
P. It is used by Dolby Vision profile 5.
Signaling color space
Coding-independent code points
Coding-independent code points (CICP) is a way to signal the properties of a video or audio stream. It can describe the color profile of videos (and still images) in a simpler way than the use of ICC profiles. It is defined in both ITU-T H.273 an ...
(CICP) are used to signal the transfer function, color primaries and matrix coefficients.
It is defined in both ITU-T H.273 and ISO/IEC 23091-2.
It is used by multiple codecs including
AVC
AVC may refer to:
Organizations
* Asian Volleyball Confederation, the continental governing body for the sport of volleyball in Asia
* Advanced Video Communications, owner of Stickam
* ¡Alfaro Vive, Carajo!, a defunct left-wing group in Ecuador
...
,
HEVC
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 compari ...
and
AVIF
AV1 Image File Format (AVIF) is an image file format specification for storing images or image sequences compressed with AV1 in the HEIF container format. It competes with HEIC, which uses the same container format built upon ISOBMFF, but HEVC f ...
. Common combinations of H.273 parameters are summarized in ITU-T Series H Supplement 19.
Metadata
Static metadata
Static HDR metadata give information about the whole video.
* SMPTE ST 2086 or MDCV (Mastering Display Color Volume): It describes the color volume of the mastering display (i.e. the color primaries, the white point and the maximum and minimum luminance). It has been defined by
SMPTE
The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the m ...
and also in
AVC
AVC may refer to:
Organizations
* Asian Volleyball Confederation, the continental governing body for the sport of volleyball in Asia
* Advanced Video Communications, owner of Stickam
* ¡Alfaro Vive, Carajo!, a defunct left-wing group in Ecuador
...
and
HEVC
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 compari ...
standards.
* MaxFALL (Maximum Frame Average Light Level)
* MaxCLL (Maximum Content Light Level)
The metadata do not describe how the HDR content should be adapted to an HDR consumer displays that have lower color volume (i.e. peak brightness, contrast and color gamut) than the content.
Dynamic metadata
Dynamic metadata are specific for each frame or each scene of the video.
Dynamic metadata of Dolby Vision, HDR10+ and SMPTE ST 2094 describe what color volume transform should be applied to contents that are shown on displays that have different color volume from the mastering display. It is optimized for each scene and each display. It allows for the creative intents to be preserved even on consumers displays that have limited color volume.
SMPTE ST 2094 or Dynamic Metadata for Color Volume Transform (DMCVT) is a standard for dynamic metadata published by
SMPTE
The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the m ...
in 2016 as six parts.
It is carried in HEVC SEI, ETSI TS 103 433, CTA 861-G. It includes four applications:
* ST 2094-10 (from Dolby Laboratories), used for Dolby Vision.
* ST 2094-20 (from Philips). Colour Volume Reconstruction Information (CVRI) is based on ST 2094–20.
* ST 2094-30 (by Technicolor). Colour Remapping Information (CRI) conforms to ST 2094-30 and is standardized in HEVC.
* ST 2094-40 (by Samsung), used for HDR10+.
ETSI TS 103 572 is a technical specification published in October 2020 by
ETSI
The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...
for HDR signaling and carriage of ST 2094-10 (Dolby Vision) metadata.
HDR Vivid uses dynamic metadata standardized in CUVA 005-2020.
Dual-layer video
Some Dolby Vision profiles use a dual-layer video composed of a base layer and an enhancement layer.
Depending on the Dolby Vision profile (or compatibility level), the base layer can be backward compatible with SDR, HDR10, HLG,
UHD Blu-ray
Ultra HD Blu-ray (4K Ultra HD, UHD-BD, or 4K Blu-ray) is a digital media, digital optical disc data storage device, data storage format that is an enhanced variant of Blu-ray. Ultra HD Blu-ray discs are incompatible with existing standard Blu-ra ...
or no other format in the most efficient IPTPQc2 color space, which uses full range and reshaping.
ETSI GS CCM 001 describes a Compound Content Management functionality for a dual-layer HDR system, including MMR (multivariate multiple regression) and NLQ (non linear quantisation).
Adoption
Guidelines
Ultra HD Forum guidelines
UHD Phase A is a set of guidelines from 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 ...
for the distribution of SDR and HDR content using Full HD 1080p and 4K UHD resolutions. It requires a color depth of 10 bits per sample, a color gamut of Rec. 709 or Rec. 2020, a
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 ...
of up to 60 fps, a display resolution of
1080p
1080p (1920×1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen vert ...
or 2160p and either standard dynamic range (SDR) or high dynamic range that uses HLG or PQ transfer functions.
UHD Phase A defines HDR as having a
dynamic range
Dynamic range (abbreviated DR, DNR, or DYR) is the ratio between the largest and smallest values that a certain quantity can assume. It is often used in the context of signals, like sound and light. It is measured either as a ratio or as a base-1 ...
of at least 13 stops (2
13=8192:1) and WCG as a color gamut that is wider than
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 ...
.
UHD Phase B will add support to 120 fps (and 120/1.001 fps), 12 bit PQ in HEVC Main12 (that will be enough for 0.0001 to 10000 nits),
Dolby AC-4 Dolby AC-4 is an audio compression technology developed by Dolby Laboratories. Dolby AC-4 bitstreams can contain audio channels and/or audio objects. Dolby AC-4 has been adopted by the DVB project and standardized by the ETSI.
History
Its developme ...
and
MPEG-H 3D Audio
MPEG-H 3D Audio, specified as ISO/IEC 23008-3 (MPEG-H Part 3), is an audio coding standard developed by the ISO/IEC Moving Picture Experts Group (MPEG) to support coding audio as audio channels, audio objects, or higher order ambisonics (HOA). MPEG ...
, IMAX sound in DTS:X (with 2 LFE). It will also add ITU's ICtCp and CRI.
Still images
HDR image formats
The following image formats are compatible with HDR (
Rec.2100 color space
A color space is a specific organization of colors. In combination with color profiling supported by various physical devices, it supports reproducible representations of colorwhether such representation entails an analog or a digital represent ...
, PQ and HLG
transfer functions, Rec.2100/Rec.2020 color primaries):
*
HEIC
High Efficiency Image File Format (HEIF) is a container format for storing individual digital images and image sequences. The standard covers multimedia files that can also include other media streams, such as timed text, audio and video.
HEI ...
(
HEVC
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 compari ...
codec in
HEIF
High Efficiency Image File Format (HEIF) is a container format for storing individual digital images and image sequences. The standard covers multimedia files that can also include other media streams, such as timed text, audio and video.
HEI ...
file format)
*
AVIF
AV1 Image File Format (AVIF) is an image file format specification for storing images or image sequences compressed with AV1 in the HEIF container format. It competes with HEIC, which uses the same container format built upon ISOBMFF, but HEVC f ...
(
AV1
AOMedia Video 1 (AV1) is an open, royalty-free video coding format initially designed for video transmissions over the Internet. It was developed as a successor to VP9 by the Alliance for Open Media (AOMedia), a consortium founded in 2015 that ...
codec in HEIF file format), supports even IC
TC
P
*
JPEG XL
JPEG XL is a royalty-free raster-graphics file format that supports both lossy and lossless compression. It is designed to outperform existing raster formats and thus become their universal replacement.
Name
The name consists of ''JPEG'' (for t ...
*HSP, CTA 2072 HDR Still Photo Interface (a format used by
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation, headquartered in Kadoma, Osaka, Kadoma, Osaka P ...
cameras for photo capture in HDR with the HLG
transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a function (mathematics), mathematical function that mathematical model, theoretically models the system's output for ...
)
Other image formats, such as
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
,
JPEG 2000
JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding the ...
,
PNG,
WebP
WebP is an image file format developed by Google intended as a replacement for JPEG, PNG, and GIF file formats. It supports both lossy and lossless compression, as well as animation and alpha transparency.
Google announced the WebP format i ...
, do not support HDR by default. They could support it by the use of the
ICC profile
In color management, an ICC profile is a set of data that characterizes a color input or output device, or a color space, according to standards promulgated by the International Color Consortium (ICC). Profiles describe the color attributes of a ...
,
but existing applications usually do not take into account the absolute luminance value defined in ICC profiles.
W3C
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working to ...
is working to add HDR support to PNG.
Adoption of HDR in still images
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation, headquartered in Kadoma, Osaka, Kadoma, Osaka P ...
: Panasonic's S-series cameras (including Lumix S1, S1R, S1H and S5) can capture photos in HDR using the HLG transfer function and output them in a HSP file format.
The captured HDR pictures can be viewed in HDR by connecting the camera to an HLG-compliant display with an HDMI cable.
A plug-in allowing the editing of HLG stills (HSP) in Photoshop CC has been released by Panasonic.
The company also released a plug-in for displaying thumbnails of those HDR images on a PC (for Windows Explorer and macOS Finder).
Canon
Canon or Canons may refer to:
Arts and entertainment
* Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base
* Literary canon, an accepted body of works considered as high culture
** Western can ...
:
EOS-1D X Mark III and
EOS R5 are able to capture still images in the Rec.2100 color space by using the PQ transfer function, the HEIC format (HEVC codec in HEIF file format), the Rec. 2020 color primaries, a bit depth of 10 bit and a 4:2:2
YCbCr
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-diffe ...
subsampling.
The captured HDR pictures can be viewed in HDR by connecting the camera to an HDR display with an HDMI cable.
Captured HDR pictures can also be converted to SDR
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
(
sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ( ...
color space) and then viewed on any standard display.
Canon refers to those SDR pictures as "HDR PQ-like JPEG". Canon's
Digital Photo Professional
Digital Photo Professional (DPP) is the software that Canon ships with its digital SLR (and some of its compacts, e.g. the Canon PowerShot S90) cameras for editing and asset management of its Canon raw (.CR2) files. It can also work with the older ...
software is able to show the captured HDR pictures in HDR on HDR displays or in SDR on SDR displays.
It is also able to convert the HDR PQ to SDR sRGB JPEG.
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 ...
:
Sony α7S III
The Sony α7S III (model ILCE-7SM3) is a 12.2-megapixel full-frame mirrorless interchangeable-lens camera made by Sony. It was publicly announced on online with a suggested retail price of (body only) at the time. The α7S III is offered as a ...
and
α1 cameras can capture HDR photos in the
Rec.2100 color space with the HLG transfer function, the HEIF format, Rec. 2020 color primaries, a bit depth of 10 bit and a 4:2:2 or 4:2:0
subsampling.
The captured HDR pictures can be viewed in HDR by connecting the camera to an HLG-compliant display with an HDMI cable.
Qualcomm
Qualcomm () is an American multinational corporation headquartered in San Diego, California, and incorporated in Delaware. It creates semiconductors, software, and services related to wireless technology. It owns patents critical to the 5G, 4 ...
:
Snapdragon 888
This is a list of Qualcomm Snapdragon systems on chips (SoC) made by Qualcomm for use in smartphones, tablets, laptops, 2-in-1 PCs, smartwatches, and smartbooks devices.
Before Snapdragon
SoC made by Qualcomm before it was renamed to Snapdr ...
mobile
SoC allows the capture of 10-bit HDR HEIF still photos.
Krita
Krita ( ) is a free and open-source raster graphics editor designed primarily for digital art and 2D animation. The software runs on Windows, macOS, Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on th ...
5.0, released on 23 December 2021, added support for HDR HEIF and AVIF images with Rec.2100 PQ and HLG encoding.
Web
Work is in progress at
W3C
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working to ...
to make Web compatible with HDR, which includes HDR capabilities detection and HDR in CSS.
History
2014
In January 2014, Dolby Laboratories announced Dolby Vision.
In August 2014, PQ was standardized in SMPTE ST 2084.
In October 2014, the HEVC specification incorporates code point for PQ. Previously, it also incorporates the Main 10 profile that supports 10 bits per sample
on their first version.
In October 2014, SMPTE standardized the Mastering Display Color Volume (MDCV) static metadata in SMPTE ST 2086.
2015
In March 2015, HLG was standardized in ARIB STD-B67.
On 8 April 2015, The HDMI Forum released version 2.0a of the HDMI Specification to enable transmission of HDR. The specification references CEA-861.3, which in turn references SMPTE ST 2084 (the standard of PQ).
The previous HDMI 2.0 version already supported the Rec. 2020 color space.
On 24 June 2015, Amazon Video was the first streaming service to offer HDR video using the HDR10 format.
On 27 August 2015, Consumer Technology Association announced HDR10.
On 17 November 2015,
Vudu
Vudu is an American digital video store and streaming service owned by Fandango Media, a joint-venture between NBCUniversal and Warner Bros. Discovery. The company offers transactional video on demand rentals and digital purchases of films, ...
announced that they had started offering titles in Dolby Vision.
2016
On 1 March 2016, the Blu-ray Disc Association released
Ultra HD Blu-ray
Ultra HD Blu-ray (4K Ultra HD, UHD-BD, or 4K Blu-ray) is a digital optical disc data storage format that is an enhanced variant of Blu-ray. Ultra HD Blu-ray discs are incompatible with existing standard Blu-ray players, though a traditional Bl ...
with mandatory support for HDR10 and optional support for Dolby Vision.
On 9 April 2016,
Netflix
Netflix, Inc. is an American subscription video on-demand over-the-top streaming service and production company based in Los Gatos, California. Founded in 1997 by Reed Hastings and Marc Randolph in Scotts Valley, California, it offers a fil ...
started offering both HDR10 and Dolby Vision.
On June to September 2016, SMPTE standardized multiple dynamic metadata for HDR in SMPTE ST 2094.
On 6 July 2016, 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) announced Rec. 2100, which defines the image parameters for HDR-TV and use two HDR
transfer functions—HLG and PQ.
On 29 July 2016, SKY Perfect JSAT Group announced that on 4 October, they would start the world's first 4K HDR broadcasts using HLG.
On 9 September 2016,
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. ...
announced
Android TV
Android TV is a smart TV operating system based on Android and developed by Google for television sets, digital media players, set-top boxes, and soundbars. A successor to Google TV, it features a user interface designed around content discovery ...
7.0, which supports Dolby Vision, HDR10, and HLG.
On 26 September 2016,
Roku
Roku ( ) is a brand of hardware digital media players manufactured by American company Roku, Inc. They offer access to streaming media content from online services.
The first Roku model, developed in collaboration with Netflix, was introduce ...
announced that the Roku Premiere+ and Roku Ultra will support HDR using HDR10.
On 7 November 2016, Google announced that
YouTube
YouTube is a global online video platform, online video sharing and social media, social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by ...
would stream HDR videos that can be encoded with HLG or PQ.
On 17 November 2016, the
Digital Video Broadcasting
Digital Video Broadcasting (DVB) is a set of international open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium, and are published by a Joint Technical Committee (JTC) ...
(DVB) Steering Board approved UHD-1 Phase 2 with a HDR solution that supports HLG and PQ.
The specification has been published as DVB Bluebook A157 and was published by the ETSI as TS 101 154 v2.3.1.
[
]
2017
On 2 January 2017, LG Electronics USA announced that all of LG's SUPER UHD TV models support a variety of HDR technologies, including Dolby Vision, HDR10, and HLG (Hybrid Log Gamma), and are ready to support Advanced HDR by Technicolor
Technicolor is a series of Color motion picture film, color motion picture processes, the first version dating back to 1916, and followed by improved versions over several decades.
Definitive Technicolor movies using three black and white films ...
.
On 20 April 2017, Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
and Amazon announced HDR10+
HDR10+ is a high dynamic range (HDR) video technology that adds dynamic metadata to HDR10 source files. The dynamic metadata are used to adjust and optimize each frame of the HDR video to the consumer display's capabilities in a way based on the ...
.
On 12 September 2017, Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
announced the Apple TV 4K with support for HDR10 and Dolby Vision, and that the iTunes Store would sell and rent 4K HDR content.
2019
On 26 December 2019, Canon
Canon or Canons may refer to:
Arts and entertainment
* Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base
* Literary canon, an accepted body of works considered as high culture
** Western can ...
announced the adoption of the PQ format (PQ10) for still photography.
2020
On 13 October 2020, Apple announced the iPhone 12
The iPhone 12 and iPhone 12 Mini (stylized and marketed as iPhone 12 mini) are a range of smartphones designed, developed, and marketed by Apple Inc. They are the fourteenth-generation, "affordable flagship" iPhones, succeeding the iPhone 11. ...
and iPhone 12 Pro
The iPhone 12 Pro and iPhone 12 Pro Max are smartphones designed, developed, and marketed by Apple Inc. They are the flagship smartphones in the fourteenth generation of the iPhone, succeeding the iPhone 11 Pro and iPhone 11 Pro Max, respec ...
series, the first smartphone that can record and edit video in Dolby Vision directly from the camera roll. iPhone uses the Dolby Vision profile 8.4 cross-compatible with HLG.
2021
In June 2021, Panasonic announced a plug-in for Photoshop CC to allow for the editing of HLG stills.
2022
On 4 July 2022, Xiaomi announced the Xiaomi 12S Ultra, the first Android smartphone that can record Dolby Vision video directly from the camera roll.
See also
* 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 = ...
References
Further reading
We need to talk about HDR
by Yoeri Geutskens
ITU-R Rep. BT.2390 "High dynamic range television for production and international programme exchange"
a report by ITU
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 ...
providing background information on HDR in general, and for the perceptual quantization
The perceptual quantizer (PQ), published by SMPTE as SMPTE ST 2084, is a transfer function that allows for HDR display by replacing the gamma curve used in SDR. It is capable of representing luminance level up to 10000 cd/m2 (nits) and down to ...
(PQ) and hybrid log–gamma
The hybrid log–gamma (HLG) transfer function is a transfer function jointly developed by the BBC and NHK for high dynamic range (HDR) display. It's backward compatible with the transfer function of SDR (the gamma curve). It was approved as ARIB S ...
(HLG) HDR signal parameters specified in the Rec.2100.
{{Dynamic range color representation
Color
Display technology
Film and video technology
High dynamic range
ITU-R recommendations
Television technology