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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 0.0001 nits. It has been developed by Dolby and standardized in 2014 by SMPTE and also in 2016 by ITU in Rec. 2100. ITU specifies the use of PQ or HLG as transfer functions for HDR-TV. PQ is the basis of HDR video formats (such as Dolby Vision, HDR10 and HDR10+) and is also used for HDR still picture formats. PQ is not backward compatible with the BT.1886 EOTF (i.e. the gamma curve of SDR), while HLG is compatible. PQ is a non-linear transfer function based on the human visual perception of banding and is able to produce no visible banding in 12 bits. A power function (used as EOTFs in standard dynamic range applications) extended to 10000 cd/m2 would have required 15 bits. Technical details The PQ EOTF (electro-optical transfer f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Society Of Motion Picture And Television Engineers
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 media and entertainment industry. As an internationally recognized standards organization, SMPTE has published more than 800 technical standards and related documents for broadcast, filmmaking, digital cinema, audio recording, information technology (IT), and medical imaging. SMPTE also publishes the ''SMPTE Motion Imaging Journal'', provides networking opportunities for its members, produces academic conferences and exhibitions, and performs other industry-related functions. SMPTE membership is open to any individual or organization with an interest in the subject matter. In the US, SMPTE is a 501(c)3 non-profit charitable organization. History The Motion Picture and Television Engineers was founded in 1913 by Charles Francis Jenkins, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 HDR video to the consumer display's capabilities in a way specified by the content creator. Dolby Vision was introduced in 2014, making it the first available consumer-oriented HDR format. HDR10+ is a competitor HDR format that also uses dynamic metadata. Dolby Vision IQ is an update designed to optimize Dolby Vision content according to the ambient light. Dolby Cinema uses Dolby Vision too; it uses 108 nits, compared to SDR cinemas' use of 48 nits and 2.6 gamma. Description HDR videos can sometimes contain brightness and color values that cannot be rendered by the consumer's display. Dolby Vision's dynamic metadata defines how each frame of the original HDR video should be adjusted to match the display's capabilities (i.e. black l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electro-optical 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 having the scene light as input and converting into the picture or video signal as output. This is typically done within a camera. The electro-optical transfer function (EOTF) is the transfer function having the picture or video signal as input and converting it into the linear light output of the display. This is done within the display device. The opto-optical transfer function (OOTF) is the transfer function having the scene light as input and the displayed light as output. The OOTF is the result of the OETF and the EOTF and is usually non- linear. List of transfer functions Linear * Raw formats *Some OETF and EOTF have an initial linear portion followed by a non-linear part (e.g. sRGB and Rec.709). Gamma * Rec. 601 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colour Banding
Colour banding is a subtle form of posterization in digital images, caused by the colour of each pixel being rounded to the nearest of the digital colour levels. While posterization is often done for artistic effect, colour banding is an undesired artifact. In 24-bit colour modes, 8 bits per channel is usually considered sufficient to render images in Rec. 709 or sRGB. However the eye can see the difference between the colour levels, especially when there is a sharp border between two large areas of adjacent color levels. This will happen with gradual gradients (like sunsets, dawns or clear blue skies), and also when blurring an image a large amount. Colour banding is more noticeable with fewer bits per pixel (BPP) at 16–256 colours (4–8 BPP), where there are fewer shades with a larger difference between them. Possible solutions include the introduction of dithering and increasing the number of bits per colour channel. Because the banding comes from limita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EOTF
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 having the scene light as input and converting into the picture or video signal as output. This is typically done within a camera. The electro-optical transfer function (EOTF) is the transfer function having the picture or video signal as input and converting it into the linear light output of the display. This is done within the display device. The opto-optical transfer function (OOTF) is the transfer function having the scene light as input and the displayed light as output. The OOTF is the result of the OETF and the EOTF and is usually non-linear. List of transfer functions Linear * Raw formats *Some OETF and EOTF have an initial linear portion followed by a non-linear part (e.g. sRGB and Rec.709). Gamma * Rec. 601, Rec. 7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-R BT
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications. Its role is to manage the international radio-frequency spectrum and satellite orbit resources and to develop standards for radiocommunication systems with the objective of ensuring the effective use of the spectrum. ITU is required, according to its constitution, to allocate spectrum and register frequency allocation, orbital positions and other parameters of satellites, “in order to avoid harmful interference between radio stations of different countries”. The international spectrum management system is therefore based on regulatory procedures for frequency coordination, notification and registration. ITU-R has a permanent secretariat, the Radiocommunication Bureau, based at the ITU HQ in Geneva, Switzerland. The electeDirector of the Bureauis Mr. Mario Maniewicz; he was first e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 content creator's intents. HDR10+ is a competitor to Dolby Vision, which also uses dynamic metadata. HDR10+ is the default variant of dynamic metadata as part of the HDMI 2.1 standard. HDR10+ Adaptive is an update designed to optimize HDR10+ content according to the ambient light. Description HDR10+, also known as HDR10 Plus, was announced on 20 April 2017, by Samsung and Amazon Video. HDR10+ updates HDR10 by adding dynamic metadata that can be used to more accurately adjust brightness levels up to 10,000 nits maximum brightness on a scene-by-scene or frame-by-frame basis and supports up to 10-bit colour depth and 8K resolution. This function is based on Samsung variant of metadata format defined in SMPTE ST 2094-40. HDR10+ is an open ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 compatible with SDR. It includes HDR static metadata but not dynamic metadata. It doesn't offer the ability to optimize content to the consumer display's capabilities in a way based on the content creator's intent. PQ10 refers to an HDR format that is same as HDR10 without any metadata. Technical details HDR10 is defined as: * EOTF: SMPTE ST 2084 ( PQ) * Bit depth: 10 bit * Color primaries: ITU-R BT.2020 (identical to BT.2100 primaries) * Static metadata: SMPTE ST 2086 (mastering display color volume), MaxFALL (maximum frame-average light level), and MaxCLL (maximum content light level) * Color sub-sampling: 4:2:0 (for compressed video sources) PQ10 refers to an HDR format that uses PQ, 10-bit and Rec. 2100 color primaries without having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 STD-B67 by the Association of Radio Industries and Businesses (ARIB). It is also defined in ATSC 3.0, Digital Video Broadcasting (DVB) UHD-1 Phase 2, and International Telecommunication Union (ITU) Rec. 2100. 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 the receiver is compatible with the BT.2020 colour container, reducing compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE Xplore
IEEE Xplore digital library is a research database for discovery and access to journal articles, conference proceedings, technical standards, and related materials on computer science, electrical engineering and electronics, and allied fields. It contains material published mainly by the Institute of Electrical and Electronics Engineers (IEEE) and other partner publishers. IEEE Xplore provides web access to more than 5 million documents from publications in computer science, electrical engineering, electronics and allied fields. Its documents and other materials comprise more than 300 peer-reviewed journals, more than 1,900 global conferences, more than 11,000 technical standards, almost 5,000 ebooks, and over 500 online courses. Approximately 20,000 new documents are added each month. Anyone can search IEEE Xplore and find bibliographic records and abstracts for its contents, while access to full-text documents may require an individual or institutional subscription. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Union, making it the oldest UN agency. The ITU was initially aimed at helping connect telegraphic networks between countries, with its mandate consistently broadening with the advent of new communications technologies; it adopted its current name in 1932 to reflect its expanded responsibilities over radio and the telephone. On 15 November 1947, the ITU entered into an agreement with the newly created United Nations to become a specialized agency within the UN system, which formally entered into force on 1 January 1949. The ITU promotes the shared global use of the radio spectrum, facilitates international cooperation in assigning satellite orbits, assists in developing and coordinating worldwide technical standards, and works to improve tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolby Laboratories
Dolby Laboratories, Inc. (often shortened to Dolby Labs and known simply as Dolby) is an American company specializing in Noise reduction#In audio, audio noise reduction, Audio data compression, audio encoding/compression, spatial audio, and High-dynamic-range television, HDR imaging. Dolby licenses its technologies to consumer electronics manufacturers. History Dolby Labs was founded by Ray Dolby (1933–2013) in London, England, in 1965. In the same year, he invented the Dolby noise-reduction system, Dolby Noise Reduction system, a form of audio signal processing for reducing the background hissing sound on audio tape recordings. His first U.S. patent on the technology was filed in 1969, four years later. The method was first used by Decca Records in the UK. He moved the company headquarters to the United States (San Francisco, California) in 1976. The first product Dolby Labs produced was the Dolby 301 unit which incorporated Type A Dolby Noise Reduction, a compander-based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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