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BT.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 resolutions, frame rates with progressive scan, bit depths, color primaries, RGB and luma-chroma color representations, chroma subsamplings, and an opto-electronic transfer function. The first version of Rec. 2020 was posted on the International Telecommunication Union (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 pixels. Frame rate Rec. 2020 sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YCbCr
YCbCr, Y′CbCr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in digital video and digital photography, photography systems. Like YPbPr, YPBPR, it is based on RGB primaries; the two are generally equivalent, but YCBCR is intended for digital video, while YPBPR is designed for use in Analogue electronics, analog systems. Y′ is the Luma (video), luma component, and CB and CR are the B-Y, blue-difference and R-Y, red-difference chrominance, chroma components. Luma Y′ (with Prime (symbol), prime) is distinguished from relative luminance, luminance Y, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries. Y′CbCr color spaces are defined by a mathematical coordinate transformation from an associated RGB primaries and white point. If the underlying RGB color spaces, RGB color space is absolute, the Y′CbCr color space is an absolute color space as well; conversely, if the RGB spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 resolution#Resolutions, 4K UHD and 8K resolution#Resolutions, 8K UHD, which are two digital video formats with an Aspect ratio (image), aspect ratio of 16:9. These were first proposed by NHK Science & Technology Research Laboratories and later defined and approved by the International Telecommunication Union (ITU). The Consumer Electronics Association announced on October 17, 2012, that "Ultra High Definition", or "Ultra HD", would be used for displays that have an display aspect ratio, aspect ratio of 16:9 or wider and at least one digital input capable of carrying and presenting native video at a minimum resolution of . In 2015, the Ultra HD Forum was created to bring together the end-to-end video production ecosystem to ensure interoperability and produce industry guidelines so that adoption of ultra-high-definition television could accelerate. Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 UHD) with a 16:9 aspect ratio is the dominant standard, whereas the digital cinema, movie projection industry uses 40962160 (Digital Cinema Initiatives, DCI 4K). The 4K television market share increased as prices fell dramatically throughout 2013 and 2014. 4K standards and terminology The term "4K" is generic and refers to any resolution with a horizontal pixel count of approximately 4,000. Several different 4K resolutions have been standardized by various organizations. The terms "4K" and "Ultra HD" are used more widely in marketing than "2160p" (''cf.'' "1080p"). While typically referring to motion pictures, some digital camera vendors have used the term "4K photo" for still photographs, making it appear like an especially high resolution even though 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chroma Subsampling
Chroma subsampling is the practice of encoding images by implementing less resolution for Chrominance, chroma information than for luma (video), luma information, taking advantage of the human visual system's lower acuity for color differences than for luminance. It is used in many video and still image encoding schemesboth analog and digitalincluding in JPEG encoding. Rationale Digital signals are often compressed to reduce file size and save transmission time. Since the human visual system is much more sensitive to variations in brightness than color, a video system can be optimized by devoting more bandwidth to the luma (video), luma component (usually denoted Y'), than to the color difference components Cb and Cr. In compressed images, for example, the 4:2:2 Y'CbCr scheme requires two-thirds the bandwidth of non-subsampled "4:4:4" R'G'B'. This reduction results in almost no visual difference as perceived by the viewer. How subsampling works The Visual perception, human vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-dynamic-range Television
High-dynamic-range television (HDR-TV) 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 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 the dynamic range of images and videos from their capture and creation to their storage, distribution and display. Often, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide Color Gamut
In color reproduction and colorimetry, a gamut, or color gamut , is a convex set containing the colors that can be accurately represented, i.e. reproduced by an output device (e.g. printer or display) or measured by an input device (e.g. camera or visual system). Devices with a larger gamut can represent more colors. Similarly, gamut may also refer to the colors within a defined color space, which is not linked to a specific device. A trichromatic gamut is often visualized as a color triangle. A less common usage defines gamut as the subset of colors contained within an image, scene or video. Introduction The term ''gamut'' was adopted from the field of music, where the medieval Latin expression "gamma ut" meant the lowest tone of the G scale and, in time, came to imply the entire range of musical notes of which musical melodies are composed. Shakespeare's use of the term in ''The Taming of the Shrew'' is sometimes attributed to the author / musician Thomas Morley. In the 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 manufacturers pushed to make 4K a new standard by 2017. At CES 2012, the first prototype 8K TVs were unveiled by Japanese electronics corporation Sharp. The feasibility of a fast transition to this new standard is questionable in view of the absence of broadcasting resources. In 2018, Strategy Analytics predicted that 8K-ready devices will still only account for 3% of UHD TVs by 2023 with global sales of 11 million units a year. However, TV manufacturers remain optimistic as the 4K market grew much faster than expected, with actual sales exceeding projections nearly six-fold in 2016. In 2013, a transmission network's capability to carry HDTV resolution was limited by internet speeds and relied on satellite broadcast to transmit the high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RGB Color Space
RGB color spaces are a category of additive colorimetric color spaces specifying part of its absolute color space definition using the RGB color model. RGB color spaces are commonly found describing the mapping of the RGB color model to human perceivable color, but some RGB color spaces use imaginary (non-real-world) primaries and thus can not be displayed directly. Like any color space, while the specifications in this category use the RGB color model to describe their space, it is not mandatory to use that model to signal pixel color values. Broadcast TV color spaces like NTSC, PAL, Rec. 709, Rec. 2020 additionally describe a translation from RGB to YCbCr and that is how they are usually signalled for transmission, but an image can be stored as either RGB or YCbCr. This demonstrates using the singular term "RGB color space" can be misleading, since a chosen color space or signalled colour can be described by any appropriate color model. However the singular can be seen in spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the application, different definitions of white are needed to give acceptable results. For example, photographs taken indoors may be lit by incandescent lights, which are relatively orange compared to daylight. Defining "white" as daylight will give unacceptable results when attempting to color-correct a photograph taken with incandescent lighting. Illuminants An illuminant is characterized by its relative spectral power distribution (SPD). The white point of an illuminant is the chromaticity of a white object under the illuminant, and can be specified by chromaticity coordinates, such as the ''x'', ''y'' coordinates on the CIE 1931 chromaticity diagram (hence the use of the relative SPD and not the absolute SPD, because the white ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 representation. A color space may be arbitrary, i.e. with physically realized colors assigned to a set of physical color swatches with corresponding assigned color names (including discrete numbers infor examplethe Pantone collection), or structured with mathematical rigor (as with the NCS System, Adobe RGB and sRGB). A "color space" is a useful conceptual tool for understanding the color capabilities of a particular device or digital file. When trying to reproduce color on another device, color spaces can show whether shadow/highlight detail and color saturation can be retained, and by how much either will be compromised. A "color model" is an abstract mathematical model describing the way colors can be represented as tuples of numbers (e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Color
Primary colors are colorants or colored lights that can be mixed in varying amounts to produce a gamut of colors. This is the essential method used to create the perception of a broad range of colors in, e.g., electronic displays, color printing, and paintings. Perceptions associated with a given combination of primary colors can be predicted by an appropriate mixing model (e.g., additive, subtractive) that uses the physics of how light interacts with physical media, and ultimately the retina to be able to accurately display the intended colors. The most common color mixing models are the additive primary colors (red, green, blue) and the subtractive primary colors (cyan, magenta, yellow). Red, yellow and blue are also commonly taught as primary colors (usually in the context of subtractive color mixing as opposed to additive color mixing), despite some criticism due to its lack of scientific basis. Primary colors can also be conceptual (not necessarily real), either as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Telecommunication Union
The International Telecommunication Union (ITU)In the other common languages of the ITU: * * is a list of specialized agencies of the United Nations, specialized agency of the United Nations responsible for many matters related to information and communications technology, information and communication technologies. It was established on 17 May 1865 as the International Telegraph Union, the first formal and permanent international organization. The organization significantly predates the UN, making it the oldest UN agency. Doreen Bogdan-Martin is the Secretary-General of ITU, the first woman to serve as its head. The ITU was initially aimed at helping connect Telegraphy, 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 cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
