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50-523: HLG is an HDR format that uses the HLG transfer function, BT.2020 color primaries and a bitdepth of 10-bit. HLG was designed to be backward compatible with SDR UHDTV . However, HLG is not intended to be fully backward compatible with traditional SDR displays that cannot interpret BT.2020 colorimetry. Both HLG transfer function and the HLG format are royalty-free . The backward compatibility allows them to be used with existing transmission standards when

100-487: A ⋅ ln ⁡ ( 12 L c − b ) + c 1 ≥ L c > 1 12 {\displaystyle V={\begin{cases}{\sqrt {3}}\cdot L_{c}^{0.5}&{\frac {1}{12}}\geq L_{c}\geq 0,\!\\a\cdot \ln(12L_{c}-b)+c&1\geq L_{c}>{\frac {1}{12}}\end{cases}}} where On May 15, 2015, the BBC announced that they had begun work with

150-418: A ln ⁡ ( 12 E − b ) + c 1 12 < E ≤ 1 {\displaystyle E'={\begin{cases}{\sqrt {3E}}\ &0\leq E\leq {\frac {1}{12}},\!\\a\ln(12E-b)+c&{\frac {1}{12}}<E\leq 1\end{cases}}} where The signal value is 0.5 for the reference white level while the signal value for 1 has a relative luminance that

200-895: A nonlinear transfer function in which the lower half of the signal values use a gamma curve and the upper half of the signal values use a logarithmic curve . HLG reference OETF is as follows (as defined in ARIB STD-B67): E ′ = { r E   0 ≤ E ≤ 1 , a ln ⁡ ( E − b ) + c 1 < E {\displaystyle E'={\begin{cases}r\,{\sqrt {E}}\ &0\leq E\leq 1,\!\\a\ln(E-b)+c&1<E\end{cases}}} or as follows (as defined in Rec. 2100 ): E ′ = { 3 E   0 ≤ E ≤ 1 12 ,

250-473: 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

300-481: 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. 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 [SMPTE ST 2084]) or hybrid log–gamma (HLG) transfer functions instead of

350-468: 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 (HLG), do not offer this possibility, so

400-406: 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, and the standards specify the required conversion depending on display capabilities. HDR-TV is a part of HDR imaging , an end-to-end process of increasing

450-438: 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. The HDR10 Media Profile, more commonly known as HDR10,

500-416: 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. When

550-408: A wide range of viewing environments. The dynamic range that can be perceived by the human eye in a single image is around 14 stops . An SDR video display with a 2.4 gamma curve and a bit depth of 8-bits per sample can display a range of about 6 stops without visible banding . Professional SDR video displays with a bit depth of 10-bits per sample extend that range to about 10 stops. When HLG

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600-1161: Is 12 times higher than the reference white level. ARIB STD-B67 has a nominal range of 0 to 12. HLG uses a logarithmic curve for the upper half of the signal values due to Weber's law . HLG reference OOTF is as follows: { F D = O O T F [ E ] = α Y S γ − 1 E R D = α Y S γ − 1 R S G D = α Y S γ − 1 G S B D = α Y S γ − 1 B S Y S = 0.2627 R S + 0.6780 G S + 0.0593 B S {\displaystyle {\begin{cases}F_{D}=OOTF[E]=\alpha Y_{S}^{\gamma -1}E\!\\R_{D}=\alpha Y_{S}^{\gamma -1}R_{S}\!\\G_{D}=\alpha Y_{S}^{\gamma -1}G_{S}\!\\B_{D}=\alpha Y_{S}^{\gamma -1}B_{S}\!\\Y_{S}=0.2627R_{S}+0.6780G_{S}+0.0593B_{S}\end{cases}}} where HLG reference EOTF

650-576: 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. (Brightness in cd/m ) (Color gamut) Color depth (Brightness in cd/m ) (Number of video frames) UHD Alliance certifications: HDR

700-409: Is a newer format that is similar to Dolby Vision, but is royalty-free. HLG is a broadcast HDR format that is used by some TV broadcasters. 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)

750-550: 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 YC B C R or IC T C P as color space . SDR uses a gamma curve 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

800-439: Is a technology that uses high dynamic range (HDR) to improve 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 more intense colors. HDR allows compatible displays to receive

850-698: Is also specified. For narrow range color, 10-bit per sample signals use video levels where the black level is defined as 64, achromatic gray level as 512 and the nominal peak as 940 in RGB, Y, and I encoding and 960 in Cb/Cr, and Ct/Cp component encoding. 12-bit per sample signals define 256 as the black level, 2048 as the gray level and the nominal peak is 3760 in RGB, Y, and I component encoding and 3840 in Cb/Cr, and Ct/Cp component encoding. Narrow range signals may extend below black or above peak white (super-black and super-white respectively), but must always be clipped to

900-429: 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 format is an HDR format that can be used for video and still images. It uses

950-409: 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

1000-529: Is an open HDR standard announced on 27 August 2015 by the Consumer Technology Association . 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

1050-502: Is as follows: F D = O O T F [ O E T F − 1 [ m a x ( 0 , ( 1 − β ) E ′ + β ) ] ] {\displaystyle F_{D}=OOTF[OETF^{-1}[max(0,(1-\beta )E'+\beta )]]} where HLG does not need to use metadata since it is compatible with both SDR displays and HDR displays. HLG can be used with displays of different brightness in

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1100-447: Is commonly associated to a WCG (a system chromaticity wider than BT.709 ). Rec. 2100 (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. Because of the increased dynamic range , HDR contents need to use more bit depth than SDR to avoid banding. While SDR uses

1150-469: Is displayed on a 2,000 cd/m display with a bit depth of 10-bits per sample it can display a range of 200,000:1 or 17.6 stops without visible banding. HLG increases the dynamic range of the video compared to a conventional gamma curve by using a logarithmic curve for the upper half of the signal values. HLG also increases the dynamic range by not including the linear part of the conventional gamma curve used by Rec. 601 and Rec. 709 . The linear part of

1200-400: Is mainly achieved by the use of PQ or HLG transfer function . 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 are used to handle the variety in displays brightness , contrast and colors. HDR video is defined in Rec. 2100. Rec. 2100

1250-534: Is not backward compatible with non-HDR displays, consumes additional bandwidth , and may also become out-of-sync or damaged in transmission. HLG defines a non-linear optical-electro transfer function , in which the lower half of the signal values use a gamma curve and the upper half of the signal values use a logarithmic curve . In practice, the signal is interpreted as normal by standard-dynamic-range displays (albeit capable of displaying more detail in highlights), but HLG-compatible displays can correctly interpret

1300-435: Is still based on and limited by the characteristics of older cathode-ray tubes (CRTs), despite the huge advances in screen and display technologies since CRT's obsolescence. SDR formats are able to represent a maximum luminance level of around 100 nits . 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

1350-450: Is the same as Rec. 2020 's. Rec. 2100 defines two sets of HDR transfer functions which are perceptual quantization (PQ) and hybrid log-gamma (HLG). HLG is supported in Rec. 2100 with a nominal peak luminance of 1,000 cd/m and a system gamma value that can be adjusted depending on background luminance. For a reference viewing environment the peak luminance of display should be 1000 cd/m or more for small area highlights and

1400-419: The Rec. 709 / sRGB 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

1450-466: The HDR capture of an Atlas V launch which was broadcast the next day on NASA TV using HLG. Vatican Television Center broadcast the ceremony of the Holy Door using HLG and the Rec. 2020 color space. Industry bodies: Hardware: Software: Broadcasters: Industry bodies: Hardware: Software: Broadcasters: HDR formats (for displays) High-dynamic-range television ( HDR-TV )

1500-458: 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

1550-836: The HDR10 format without any metadata. It uses the perceptual quantizer (PQ) transfer function, Rec. 2020 color primaries and a bit depth of 10-bits. 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. Yearly license (for manufacturer) 1,000 - 4,000 nits (common) 1,000 - 4,000 nits (common) 4,000 nits common TV sets with enhanced dynamic range and upscaling of existing SDR/LDR video/broadcast content with reverse tone mapping have been anticipated since early 2000s. In 2016, HDR conversion of SDR video

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1600-452: The HLG transfer function, Rec. 2020 color primaries, and a bit depth of 10 bits. The format is backwards compatible with SDR UHDTV , 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 , 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

1650-1188: The NHK to develop a joint HDR proposal that would be proposed to the International Telecommunication Union (ITU). On June 9, 2015, HLG was proposed to the JCT-VC for High Efficiency Video Coding (HEVC) and added to the June 2015 draft of the screen content coding extensions. Later that year, Sony showed HLG video on a modified HDR display at the SMPTE 2015 conference. Colorfront announced that their Transkoder 2016 software would support HDR output using HLG. LG announced that their 2015 4K OLED TVs would support HDR from HLG and perceptual quantizer (PQ). Blackmagic Design released an update for DaVinci Resolve that added support for HLG. SKY PerfecTV! announced that they will use HLG to transmit 4K UHDTV HDR programming to their satellite subscribers in Japan. Harmonic Inc. and NASA announced

1700-539: The black level should be 0.005 cd/m or less. The surround light should be 5 cd/m and be neutral grey at standard illuminant D 65 . Within each set, the documented transfer functions include an: Rec. 2100 uses the same color primaries as Rec. 2020 which is a Wide Color Gamut . Rec. 2100 specifies three resolutions of 1920 × 1080 ("Full HD"), 3840 × 2160 ("4K UHD"), and 7680 × 4320 ("8K UHD"). These resolutions have an aspect ratio of 16:9 and use square pixels . Rec. 2100 specifies

1750-411: 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

1800-438: The content creator's intents are not ensured to be preserved on less 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. Since 2014, multiple HDR formats have emerged including HDR10 , HDR10+ , Dolby Vision , and HLG. Some formats are royalty-free and others require

1850-651: The conventional gamma curve was used to limit camera noise in low light video but is no longer needed with HDR cameras . HLG is supported in Rec. 2100 with a nominal peak luminance of 1,000 cd/m and a system gamma value that can be adjusted depending on background luminance. HLG is supported in HEVC with a formula that is mathematically equivalent to ARIB STD-B67 but has a nominal range of 0 to 1 instead of 0 to 12: V = { 3 ⋅ L c 0.5 1 12 ≥ L c ≥ 0 ,

1900-535: The dynamic range of images and videos from their capture and creation to their storage, distribution and display. Often, HDR is used with wide color gamut (WCG) technology. WCG increases the gamut and number of distinct colors available. HDR increases the range of luminance available for each color. HDR and WCG are separable but complementary technologies. Standards-compliant HDR display also has WCG capabilities, as mandated by Rec. 2100 and other common HDR specifications. The use of HDR in television sets began in

1950-406: The following frame rates: 120p, 119.88p, 100p, 60p, 59.94p, 50p, 30p, 29.97p, 25p, 24p, 23.976p. Only progressive scan frame rates are allowed. Rec. 2100 specifies a bit depth of either 10-bits per sample or 12-bits per sample, with either narrow range or full range color values. A future-use and intermediate linear RGB format using IEEE 16 bit floating point representation for each channel

2000-576: 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 use 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 and full-array LED-backlighting , to more properly display advanced contrast. The DisplayHDR standard from VESA

2050-449: The late 2010s. By 2020, most high-end and mid-range TVs supported HDR, and some budget models did as well. HDR-TVs are now the standard for most new televisions. There are a number of different HDR formats, including HDR10 , HDR10+ , Dolby Vision , and HLG . HDR10 is the most common format, and is supported by all HDR-TVs. Dolby Vision is a more advanced format that offers some additional features, such as scene-by-scene mastering. HDR10+

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2100-422: 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. 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

2150-545: The logarithmic portion of the signal curve to provide a wider dynamic range. In contrast with the other HDR formats it does not use metadata. The HLG transfer function is backward compatible with SDR 's gamma curve . However, HLG is commonly used with Rec. 2020 color primaries which produce a de- saturated image with visible hue shifts on non-compatible devices. HLG is therefore backward compatible with SDR- UHDTV and will show color distortion on common SDR devices that only support Rec. 709 color primaries. HLG defines

2200-488: The receiver is compatible with the BT.2020 colour container, reducing complexity and cost for both equipment manufacturers and content distributors. They are supported by HDMI 2.0b, HEVC , VP9 , and H.264/MPEG-4 AVC , and are used by video services such as BBC iPlayer , DirecTV , Freeview Play , and YouTube . HLG is designed to be better-suited for television broadcasting , where the metadata required for other HDR formats

2250-429: The signal range of 4-1019 for 10-bit signals or 16-4079 for 12-bit signals. Rec. 2100 specifies the use of RGB, YCbCr, and ICtCp. ICtCp provides an improved color representation that is designed for high dynamic range (HDR) and wide color gamut signals (WCG). Rec. 2100 allows for RGB , YCbCr , and ICtCp signal formats with 4:4:4, 4:2:2, and 4:2:0 chroma subsampling . Rec. 2100 specifies that if

2300-415: The traditional " gamma " previously used for SDR -TV. It defines various aspects of HDR-TV such as display resolution ( HDTV and UHDTV ), frame rate , chroma subsampling , bit depth , color space , color primaries , white point , and transfer function . It was posted on the International Telecommunication Union (ITU) website on July 4, 2016. Rec. 2100 uses a wide color gamut (WCG) which

2350-415: 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: SDR for HD video uses a system chromaticity ( chromaticity of color primaries and white point ) specified in Rec. 709 (same as sRGB ). SDR for SD used many different primaries, as said in BT.601, SMPTE 170M and BT.470. HDR

2400-476: The video) is mediated by the display, with the result that the original producer's intent may not be preserved. 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+, also known as HDR10 Plus,

2450-509: Was released in April 2015 and DisplayPort 1.4, which was released in March 2016. On 12 December 2016, HDMI announced that HLG support had been added to the HDMI 2.0b standard. HDMI 2.1 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. As of 2020, no display is capable of rendering

2500-476: Was released to market as Samsung 's HDR+ (in LCD TV sets) and Technicolor SA's HDR Intelligent Tone Management. As of 2018, high-end consumer-grade HDR displays can achieve 1,000 cd/m of luminance, at least for a short duration or over a small portion of the screen, compared to 250-300 cd/m for a typical SDR display. Video interfaces that support at least one HDR Format include HDMI 2.0a, which

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