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YUV
YUV is a color model typically used as part of a color image pipeline. It encodes a color image or video taking human perception into account, allowing reduced bandwidth for chrominance components, compared to a "direct" RGB-representation. Historically, the terms YUV and Y′UV were used for a specific ''analog encoding'' of color information in television systems. Today, the term YUV is commonly used in the computer industry to describe colorspaces that are encoded using YCbCr. The YUV model defines one luminance component (Y) meaning physical linear-space brightness, and two chrominance components, called U (blue projection) and V (red projection) respectively. It can be used to convert to and from the RGB model, and with different color spaces. The closely related Y′UV model uses the luma component (Y′) – nonlinear perceptual brightness, with the prime symbols (') denoting gamma correction. Y′UV is used in the PAL analogue color TV standard (excluding PAL-N). Previo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YUV UV Plane
YUV is a color model typically used as part of a color image pipeline. It encodes a color image or video taking human perception into account, allowing reduced bandwidth for chrominance components, compared to a "direct" RGB-representation. Historically, the terms YUV and Y′UV were used for a specific ''analog encoding'' of color information in television systems. Today, the term YUV is commonly used in the computer industry to describe colorspaces that are encoded using YCbCr. The YUV model defines one luminance component (Y) meaning physical linear-space brightness, and two chrominance components, called U (blue projection) and V (red projection) respectively. It can be used to convert to and from the RGB model, and with different color spaces. The closely related Y′UV model uses the luma component (Y′) – nonlinear perceptual brightness, with the prime symbols (') denoting gamma correction. Y′UV is used in the PAL analogue color TV standard (excluding PAL-N). Previo ... [...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.g. tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YDbDr
YDbDr, sometimes written YDBDR, is the colour space used in the SECAM analog terrestrial colour television broadcasting standard (adopted in France and some countries of the former Eastern Bloc) and PAL-N (adopted in Argentina, Paraguay and Uruguay). It is very close to YUV (used on the PAL system) and its related colour spaces such as YIQ (used on the NTSC system), YPbPr and YCbCr. YDbDr is composed of three components - Y, D_B and D_R. Y is the luminance, D_B and D_R are the chrominance components, representing the red and blue colour differences. Formulas The three component signals are created from an original RGB (red, green and blue) source. The weighted values of R, G and B are added together to produce a single Y signal, representing the overall brightness, or luminance, of that spot. The D_B signal is then created by subtracting the Y from the blue signal of the original RGB, and then scaling; and D_R by subtracting the Y from the red, and then scaling by a different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, 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 space is absolute, the Y′CbCr color space is an absolute color space as well; conversely, if the RGB space is ill-defined, so is Y′CbCr. The transformation is defined iITU-T H.273 Nevertheless that rule does not apply to P3-D65 primaries used by Netflix with BT.2020-NCL matrix, so that means matrix was not derived from primaries, but now Netflix allows BT.2020 primaries (since 2021). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. Since its introduction in 1992, JPEG has been the most widely used image compression standard in the world, and the most widely used digital image format, with several billion JPEG images produced every day as of 2015. The term "JPEG" is an acronym for the Joint Photographic Experts Group, which created the standard in 1992. JPEG was largely responsible for the proliferation of digital images and digital photos across the Internet, and later social media. JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; along with JPEG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YPbPr
YPbPr or Y'PbPr, also written as , is a color space used in video electronics, in particular in reference to component video cables. YPBPR is gamma corrected YCBCR color space (it is not analog YUV that was used for analog TV, though component video is an analog interface); the two are numerically equivalent but YPBPR is designed for use in analog systems while YCBCR is intended for digital video. The EOTF (gamma correction) may be different from common sRGB EOTF and BT.1886 EOTF. Sync is carried on the Y channel and is a bi-level sync signal, however, in HD formats a tri-level sync is used and is typically carried on all channels. YPBPR is commonly referred to as ''component video'' by manufacturers; however, there are many types of component video, most of which are some form of RGB. Some video cards come with video-in video-out (VIVO) ports for connecting to component video devices. Technical details YPBPR is converted from the RGB video signal, which is split into th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''color sequential with memory''), is an analog color television system that was used in France, some parts of Europe and Africa, and Russia. It was one of three major analog color television standards, the others being PAL and NTSC. This page primarily discusses the SECAM colour encoding system. The articles on broadcast television systems and analog television further describe frame rates, image resolution, and audio modulation. SECAM video is composite video because the luminance (luma, monochrome image) and chrominance (chroma, color applied to the monochrome image) are transmitted together as one signal. All the countries using SECAM are currently in the process of conversion, or have already converted to Digital Video Broadcasting (DVB), the new pan-European standard for digital television. SECAM remained a major standard into the 2000s. History Development of SECAM predates PAL, and be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 = A V_\text^\gamma, where the non-negative real input value V_\text is raised to the power \gamma and multiplied by the constant ''A'' to get the output value V_\text. In the common case of , inputs and outputs are typically in the range 0–1. A gamma value \gamma 1 is called a ''decoding gamma'', and the application of the expansive power-law nonlinearity is called gamma expansion. Explanation Gamma encoding of images is used to optimize the usage of bits when encoding an image, or bandwidth used to transport an image, by taking advantage of the non-linear manner in which humans perceive light and color. The human perception of brightness ( lightness), under common illumination conditions (neither pitch black nor blindingly bright), fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luma (video)
In video, luma represents the brightness in an image (the "black-and-white" or achromatic portion of the image). Luma is typically paired with chrominance. Luma represents the achromatic image, while the chroma components represent the color information. Converting R′G′B′ sources (such as the output of a three-CCD camera) into luma and chroma allows for chroma subsampling: because human vision has finer spatial sensitivity to luminance ("black and white") differences than chromatic differences, video systems can store and transmit chromatic information at lower resolution, optimizing perceived detail at a particular bandwidth. Luma versus relative luminance Luma is the weighted sum of gamma-compressed R′G′B′ components of a color video—the ''prime symbols'' ′ denote gamma compression. The word was proposed to prevent confusion between luma as implemented in video engineering and relative luminance as used in color science (i.e. as defined by CIE). Relative lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrominance
Chrominance (''chroma'' or ''C'' for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying luma signal (or Y' for short). Chrominance is usually represented as two color-difference components: U = B′ − Y′ (blue − luma) and V = R′ − Y′ (red − luma). Each of these difference components may have scale factors and offsets applied to it, as specified by the applicable video standard. In composite video signals, the U and V signals modulate a color subcarrier signal, and the result is referred to as the chrominance signal; the phase and amplitude of this modulated chrominance signal correspond approximately to the hue and saturation of the color. In digital-video and still-image color spaces such as Y′CbCr, the luma and chrominance components are digital sample values. Separating RGB color signals into luma and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Image Pipeline
An image pipeline or video pipeline is the set of components commonly used between an image source (such as a camera, a scanner, or the rendering engine in a computer game), and an image renderer (such as a television set, a computer screen, a computer printer or cinema screen), or for performing any intermediate digital image processing consisting of two or more separate processing blocks. An image/video pipeline may be implemented as computer software, in a digital signal processor, on an FPGA, or as fixed-function ASIC. In addition, analog circuits can be used to do many of the same functions. Typical components include image sensor corrections (including debayering or applying a Bayer filter), noise reduction, image scaling, gamma correction, image enhancement, colorspace conversion (between formats such as RGB, YUV or YCbCr), chroma subsampling, framerate conversion, image compression/video compression (such as JPEG), and computer data storage/data transmission. Typical goals o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CIELUV
In colorimetry, the CIE 1976 ''L''*, ''u''*, ''v''* color space, commonly known by its abbreviation CIELUV, is a color space adopted by the International Commission on Illumination (CIE) in 1976, as a simple-to-compute transformation of the 1931 CIE XYZ color space, but which attempted perceptual uniformity. It is extensively used for applications such as computer graphics which deal with colored lights. Although additive mixtures of different colored lights will fall on a line in CIELUV's uniform chromaticity diagram (called the ''CIE 1976 UCS''), such additive mixtures will not, contrary to popular belief, fall along a line in the CIELUV color space unless the mixtures are constant in lightness. Historical background CIELUV is an Adams chromatic valence color space and is an update of the CIE 1964 (''U''*, ''V''*, ''W''*) color space (CIEUVW). The differences include a slightly modified lightness scale and a modified uniform chromaticity scale, in which one of the coordinate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
