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Y′UV
Y′UV, also written YUV, is the color model found in the PAL analogue color TV standard. A color is described as a Y′ component ( luma) and two chroma components U and V. The prime symbol (') denotes that the luma is calculated from gamma-corrected RGB input and that it is different from true luminance. Today, the term YUV is commonly used in the computer industry to describe colorspaces that are encoded using YCbCr.Poynton, Charles. "YUV and ''luminance'' considered harmful: A plea for precise terminology in video/ref> In TV formats, color information (U and V) was added separately via a subcarrier so that a black-and-white receiver would still be able to receive and display a color picture transmission in the receiver's native black-and-white format, with no need for extra transmission bandwidth. As for etymology, Y, Y′, U, and V are not abbreviations. The use of the letter Y for luminance can be traced back to the choice of XYZ primaries. This lends itself natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. It was one of three major analog color television standards, the others being PAL and NTSC. Like PAL, a SECAM picture is also made up of 625 interlaced lines and is displayed at a rate of 25 frames per second (except SECAM-M). However, due to the way SECAM processes color information, it is not compatible with the PAL video format standard. SECAM video is composite video; 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 have either converted to DVB, Digital Video Broadcasting (DVB), the new pan-European standard for digital television, or are currently in the Digital television transition, process of conversion. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YDbDr
YDbDr, sometimes written YD_BD_R, is the colour space used in the SECAM (adopted in France and some countries of the former Eastern Bloc) analog colour television broadcasting standard. 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. YD_BD_R is composed of three components: Y, D_B and D_R. Y is the 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 wit ..., 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 ... [...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] |
Color Difference
In color science, color difference or color distance is the separation between two colors. This metric allows quantified examination of a notion that formerly could only be described with adjectives. Quantification of these properties is of great importance to those whose work is color-critical. Common definitions make use of the Euclidean distance in a device-independent color space. Euclidean sRGB As most definitions of color difference are distances within a color space, the standard means of determining distances is the Euclidean distance. If one presently has an RGB (red, green, blue) tuple and wishes to find the color difference, computationally one of the easiest is to consider ''R'', ''G'', ''B'' linear dimensions defining the color space. A very simple example can be given between the two colors with RGB values (0, 64, 0) () and (255, 64, 0) (): their distance is 255. Going from there to (255, 64, 128) () is a distance of 128. When we wish to calculate distance from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grayscale Image
In digital photography, computer-generated imagery, and colorimetry, a greyscale (more common in Commonwealth English) or grayscale (more common in American English) image is one in which the value of each pixel is a single sample (signal), sample representing only an ''amount'' of light; that is, it carries only luminous intensity, intensity information. Grayscale images, are black-and-white or gray monochrome, and composed exclusively of shades of gray. The contrast (vision), contrast ranges from black at the weakest intensity to white at the strongest. Grayscale images are distinct from one-bit bi-tonal black-and-white images, which, in the context of computer imaging, are images with only two colors: black and white (also called ''bilevel'' or ''binary images''). Grayscale images have many shades of gray in between. Grayscale images can be the result of measuring the intensity of light at each pixel according to a particular weighted combination of frequencies (or wavelen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG
JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) 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 trade off between storage size and image quality. JPEG typically achieves 10:1 compression with noticeable, but widely agreed to be acceptable 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 Joint Photographic Experts Group created the standard in 1992, based on the discrete cosine transform (DCT) algorithm. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Television
Color television (American English) or colour television (British English) is a television transmission technology that also includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white television technology, which displays the image in shades of gray (grayscale). Television broadcasting stations and networks in most parts of the world upgraded from black-and-white to color transmission between the 1960s and the 1980s. The invention of color television standards was an important part of the history of television, history and technology of television. Transmission of color images using mechanical scanners had been conceived as early as the 1880s. A demonstration of mechanically scanned color television was given by John Logie Baird in 1928, but its limitations were apparent even then. Development of electronic scanning and display made a practical system possible. Monochrome transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model, used on television and computer screens, it is one of the additive primary colors, along with red and blue, which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll, the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage. Several minerals have a green color, including the emerald, which is colored green by its chromium content. During post-classical and early modern Europe, green was the color commonly associated with wealth, merchants, bankers, and the gentry, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RGB Color Model
The RGB color model is an additive color, 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 additive primary colors, red, green, and blue. The main purpose of the RGB color model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography and Light-emitting diode#RGB systems, colored lighting. Before the electronic age, the RGB color model already had a solid theory behind it, based in Trichromacy, human perception of colors. RGB is a ''device-dependent'' color model: different devices detect or reproduce a given RGB value differently, since the color elements (such as phosphors or dyes) and their response to the individual red, green, and blue levels vary from manufacturer to manufacturer, or even in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Component Video
Digital component video is defined by the ITU-R BT.601 (formerly CCIR 601) standard and uses the Y'CbCr colorspace. The specific encoding of ITU-R BT.656 was used to transmit uncompressed analog standard-definition television component signals in a multiplexed digital format. Like analog component video,The common name for 'component analog video (CAV)' it gets its name from the fact that the video signal has been split into two or more components, that are then carried on multiple conductors between devices. Digital component video is used in both computer and home-theatre applications, such as . It was the internal signalling ''(as opposed to, e.g. RGB)'' in MiniDV, DV, and Digital Betacam Component video can carry signals such as 480i, 480p, 576i, 576p, 720p, 1080i and 1080p, although many TVs do not support 1080p through component video. See also * Serial digital interface Serial digital interface (SDI) is a family of digital video Interface (computing), in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue
Blue is one of the three primary colours in the RYB color model, RYB colour model (traditional colour theory), as well as in the RGB color model, RGB (additive) colour model. It lies between Violet (color), violet and cyan on the optical spectrum, spectrum of visible light. The term ''blue'' generally describes colours perceived by humans observing light with a dominant wavelength that's between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; Azure (color), azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering#Cause of the blue colour of the sky, Rayleigh scattering. An optical effect called the Tyndall effect explains Eye color#Blue, blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective. Blue has been an important colour in art and decoration since ancient t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
