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113-635: 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 in equations 32, 33 in ITU-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

226-399: A coordinate system is the identification of points on a line with real numbers using the number line . In this system, an arbitrary point O (the origin ) is chosen on a given line. The coordinate of a point P is defined as the signed distance from O to P , where the signed distance is the distance taken as positive or negative depending on which side of the line P lies. Each point

339-444: A cornfield, painted shortly before he died, was particularly agitated and haunting. In the late 19th century, black also became the color of anarchism . (See the section political movements .) In the 20th century, black was utilised by Italian and German fascism . (See the section political movements ). In art, the colour regained some of the territory that it had lost during the 19th century. The Russian painter Kasimir Malevich ,

452-668: A famous theological dispute broke out between the Cistercian monks, who wore white, and the Benedictines, who wore black. A Benedictine abbot, Pierre the Venerable, accused the Cistercians of excessive pride in wearing white instead of black. Saint Bernard of Clairvaux , the founder of the Cistercians responded that black was the color of the devil, hell, "of death and sin", while white represented "purity, innocence and all

565-526: A goat, a dog, a wolf, a bear, a deer or a rooster, accompanied by their familiar spirits , black cats, serpents and other black creatures. This was the origin of the widespread superstition about black cats and other black animals. In medieval Flanders , in a ceremony called Kattenstoet, black cats were thrown from the belfry of the Cloth Hall of Ypres to ward off witchcraft. Witch trials were common in both Europe and America during this period. During

678-402: A letter, as in "the x -coordinate". The coordinates are taken to be real numbers in elementary mathematics , but may be complex numbers or elements of a more abstract system such as a commutative ring . The use of a coordinate system allows problems in geometry to be translated into problems about numbers and vice versa ; this is the basis of analytic geometry . The simplest example of

791-400: A lot of redundancy . YCbCr and Y′CbCr are a practical approximation to color processing and perceptual uniformity, where the primary colors corresponding roughly to red, green and blue are processed into perceptually meaningful information. By doing this, subsequent image/video processing, transmission and storage can do operations and introduce errors in perceptually meaningful ways. Y′CbCr

904-512: A luminous black. These are parallelled in Middle English by the terms swart for dull black and blaek for luminous black. Swart still survives as the word swarthy , while blaek became the modern English black . The former is cognate with the words used for black in most modern Germanic languages aside from English ( German : schwarz , Dutch : zwart , Swedish : svart , Danish : sort , Icelandic : svartr ). In heraldry,

1017-420: A man she loves." French designer Jean Patou also followed suit by creating a black collection in 1929. Other designers contributed to the trend of the little black dress . The Italian designer Gianni Versace said, "Black is the quintessence of simplicity and elegance," and French designer Yves Saint Laurent said, "black is the liaison which connects art and fashion. One of the most famous black dresses of

1130-423: A matrix. The decoding matrix for BT.2020-NCL is this with 14 decimal places: The smaller values in the matrix are not rounded; they are precise values. For systems with limited precision (8 or 10 bit, for example) a lower precision of the above matrix could be used, for example, retaining only 6 digits after decimal point. The CL version, YcCbcCrc, codes: The CL function can be used when preservation of luminance

1243-568: A member of the Suprematist movement, created the Black Square in 1915, is widely considered the first purely abstract painting. He wrote, "The painted work is no longer simply the imitation of reality, but is this very reality ... It is not a demonstration of ability, but the materialization of an idea." Black was appreciated by Henri Matisse . "When I didn't know what color to put down, I put down black," he said in 1945. "Black

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1356-492: A mixture of nitrobenzene , aniline and aniline hydrochloride in the presence of a copper or iron catalyst . Its main industrial uses are as a colorant for lacquers and varnishes and in marker-pen inks. The first known inks were made by the Chinese, and date back to the 23rd century B.C. They used natural plant dyes and minerals such as graphite ground with water and applied with an ink brush . Early Chinese inks similar to

1469-401: A modified Rec. 601 Y′CbCr where Y′, C B and C R have the full 8-bit range of [0...255]. Below are the conversion equations expressed to six decimal digits of precision. (For ideal equations, see ITU-T T.871.) Note that for the following formulae, the range of each input (R,G,B) is also the full 8-bit range of [0...255]. And back: The above conversion is identical to sYCC when the input

1582-404: A point are the signed distances to each of the planes. This can be generalized to create n coordinates for any point in n -dimensional Euclidean space. Depending on the direction and order of the coordinate axes , the three-dimensional system may be a right-handed or a left-handed system. Another common coordinate system for the plane is the polar coordinate system . A point is chosen as

1695-476: A point varies while the other coordinates are held constant, then the resulting curve is called a coordinate curve . If a coordinate curve is a straight line , it is called a coordinate line . A coordinate system for which some coordinate curves are not lines is called a curvilinear coordinate system . Orthogonal coordinates are a special but extremely common case of curvilinear coordinates. A coordinate line with all other constant coordinates equal to zero

1808-399: A result, a similar set of subsampling techniques can be used. These coefficients are not in use and were never in use. H.273 also describes constant and non-constant luminance systems which are derived strictly from primaries and white point, so that situations like sRGB/BT.709 default primaries of JPEG that use BT.601 matrix (that is derived from BT.470-6 System M) do not happen. Prior to

1921-460: A second (typically referred to as "local") coordinate system, fixed to the node, is defined based on the first (typically referred to as "global" or "world" coordinate system). For instance, the orientation of a rigid body can be represented by an orientation matrix , which includes, in its three columns, the Cartesian coordinates of three points. These points are used to define the orientation of

2034-438: A studio range of 16–240 for U and V. (These ranges are important in video editing and production, since using the wrong range will result either in an image with "clipped" blacks and whites, or a low-contrast image.) These matrices round all factors to the closest 1/256 unit. As a result, only one 16-bit intermediate value is formed for each component, and a simple right-shift with rounding (x + 128) >> 8 can take care of

2147-535: A trade-off to improved computation speeds. Y′ values are conventionally shifted and scaled to the range [16, 235] (referred to as studio swing or "TV levels") rather than using the full range of [0, 255] (referred to as full swing or "PC levels"). This practice was standardized in SMPTE-125M in order to accommodate signal overshoots ("ringing") due to filtering. U and V values, which may be positive or negative, are summed with 128 to make them always positive, giving

2260-455: Is a color that results from the absence or complete absorption of visible light . It is an achromatic color, without hue , like white and grey . It is often used symbolically or figuratively to represent darkness . Black and white have often been used to describe opposites such as good and evil , the Dark Ages versus Age of Enlightenment , and night versus day . Since

2373-405: Is a homeomorphism from an open subset of a space X to an open subset of R . It is often not possible to provide one consistent coordinate system for an entire space. In this case, a collection of coordinate maps are put together to form an atlas covering the space. A space equipped with such an atlas is called a manifold and additional structure can be defined on a manifold if the structure

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2486-417: Is a black which is made from the tendrils of vines. And these tendrils need to be burned. And when they have been burned, throw some water onto them and put them out and then mull them in the same way as the other black. And this is a lean and black pigment and is one of the perfect pigments that we use." Cennini also noted that "There is another black which is made from burnt almond shells or peaches and this

2599-444: Is a force: I used black as ballast to simplify the construction ... Since the impressionists it seems to have made continuous progress, taking a more and more important part in color orchestration, comparable to that of the double bass as a solo instrument." In the 1950s, black came to be a symbol of individuality and intellectual and social rebellion, the color of those who did not accept established norms and values. In Paris, it

2712-507: Is a perfect, fine black." Similar fine blacks were made by burning the pits of the peach, cherry or apricot. The powdered charcoal was then mixed with gum arabic or the yellow of an egg to make a paint. Different civilizations burned different plants to produce their charcoal pigments. The Inuit of Alaska used wood charcoal mixed with the blood of seals to paint masks and wooden objects. The Polynesians burned coconuts to produce their pigment. Good-quality black dyes were not known until

2825-433: Is a species of flowering tree in the legume family, Fabaceae , that is native to southern Mexico and northern Central America. The modern nation of Belize grew from 17th century English logwood logging camps. Since the mid-19th century, synthetic black dyes have largely replaced natural dyes. One of the important synthetic blacks is Nigrosin , a mixture of synthetic black dyes (CI 50415, Solvent black 5) made by heating

2938-422: Is added to the r and θ polar coordinates giving a triple ( r ,  θ ,  z ). Spherical coordinates take this a step further by converting the pair of cylindrical coordinates ( r ,  z ) to polar coordinates ( ρ ,  φ ) giving a triple ( ρ ,  θ ,  φ ). A point in the plane may be represented in homogeneous coordinates by a triple ( x ,  y ,  z ) where x / z and y / z are

3051-414: Is called a coordinate axis , an oriented line used for assigning coordinates. In a Cartesian coordinate system , all coordinates curves are lines, and, therefore, there are as many coordinate axes as coordinates. Moreover, the coordinate axes are pairwise orthogonal . A polar coordinate system is a curvilinear system where coordinate curves are lines or circles . However, one of the coordinate curves

3164-417: Is consistent where the coordinate maps overlap. For example, a differentiable manifold is a manifold where the change of coordinates from one coordinate map to another is always a differentiable function. In geometry and kinematics , coordinate systems are used to describe the (linear) position of points and the angular position of axes, planes, and rigid bodies . In the latter case, the orientation of

3277-505: Is derived as follows: Digital Y′CbCr (8 bits per sample) is derived from analog R'G'B' as follows: or simply componentwise The resultant signals range from 16 to 235 for Y′ (Cb and Cr range from 16 to 240); the values from 0 to 15 are called footroom , while the values from 236 to 255 are called headroom . The same quantisation ranges, different for Y and Cb, Cr also apply to BT.2020 and BT.709. Alternatively, digital Y′CbCr can derived from digital R'dG'dB'd (8 bits per sample, each using

3390-501: Is described by coordinate transformations , which give formulas for the coordinates in one system in terms of the coordinates in another system. For example, in the plane, if Cartesian coordinates ( x ,  y ) and polar coordinates ( r ,  θ ) have the same origin, and the polar axis is the positive x axis, then the coordinate transformation from polar to Cartesian coordinates is given by x  =  r  cos θ and y  =  r  sin θ . With every bijection from

3503-566: Is further defined in SMPTE ST 2084 and BT.2100 . BT.2100 will introduce the use of IC T C P , a semi-perceptual colorspace derived from linear RGB with good hue linearity. It is "near-constant luminance". The SMPTE 240M standard (used on the MUSE analog HD television system) defines YCC with these coefficients: The coefficients are derived from SMPTE 170M primaries and white point, as used in 240M standard. JFIF usage of JPEG supports

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3616-407: Is given a unique coordinate and each real number is the coordinate of a unique point. The prototypical example of a coordinate system is the Cartesian coordinate system . In the plane , two perpendicular lines are chosen and the coordinates of a point are taken to be the signed distances to the lines. In three dimensions, three mutually orthogonal planes are chosen and the three coordinates of

3729-515: Is given as sRGB, except that IEC 61966-2-1:1999/Amd1:2003 only gives four decimal digits. JPEG also defines a "YCCK" format from Adobe for CMYK input. In this format, the "K" value is passed as-is, while CMY are used to derive YCbCr with the above matrix by assuming R = 1 − C {\displaystyle R=1-C} , G = 1 − M {\displaystyle G=1-M} , and B = 1 − Y {\displaystyle B=1-Y} . As

3842-547: Is of primary importance (see: Chroma subsampling § Gamma luminance error ), or when "there is an expectation of improved coding efficiency for delivery." The specification refers to Report ITU-R BT.2246 on this matter. BT.2246 states that CL has improved compression efficiency and luminance preservation, but NCL will be more familiar to a staff that has previously handled color mixing and other production practices in HDTV YCbCr. BT.2020 does not define PQ and thus HDR, it

3955-418: Is reduced to a single point, the origin, which is often viewed as a circle of radius zero. Similarly, spherical and cylindrical coordinate systems have coordinate curves that are lines, circles or circles of radius zero. Many curves can occur as coordinate curves. For example, the coordinate curves of parabolic coordinates are parabolas . In three-dimensional space, if one coordinate is held constant and

4068-482: Is represented by many pairs of coordinates. For example, ( r ,  θ ), ( r ,  θ +2 π ) and (− r ,  θ + π ) are all polar coordinates for the same point. The pole is represented by (0, θ ) for any value of θ . There are two common methods for extending the polar coordinate system to three dimensions. In the cylindrical coordinate system , a z -coordinate with the same meaning as in Cartesian coordinates

4181-943: Is the most common ink color used for printing books, newspapers and documents, as it provides the highest contrast with white paper and thus is the easiest color to read. Similarly, black text on a white screen is the most common format used on computer screens. As of September 2019, the darkest material is made by MIT engineers from vertically aligned carbon nanotubes . The word black comes from Old English blæc ("black, dark", also , "ink"), from Proto-Germanic * blakkaz ("burned"), from Proto-Indo-European * bhleg- ("to burn, gleam, shine, flash"), from base * bhel- ("to shine"), related to Old Saxon blak ("ink"), Old High German blach ("black"), Old Norse blakkr ("dark"), Dutch blaken ("to burn"), and Swedish bläck ("ink"). More distant cognates include Latin flagrare ("to blaze, glow, burn"), and Ancient Greek phlegein ("to burn, scorch"). The Ancient Greeks sometimes used

4294-523: Is the systems of homogeneous coordinates for points and lines in the projective plane. The two systems in a case like this are said to be dualistic . Dualistic systems have the property that results from one system can be carried over to the other since these results are only different interpretations of the same analytical result; this is known as the principle of duality . There are often many different possible coordinate systems for describing geometrical figures. The relationship between different systems

4407-440: Is used to separate out a luma signal (Y′) that can be stored with high resolution or transmitted at high bandwidth, and two chroma components (C B and C R ) that can be bandwidth-reduced, subsampled, compressed, or otherwise treated separately for improved system efficiency. One practical example would be decreasing the bandwidth or resolution allocated to "color" compared to "black and white", since humans are more sensitive to

4520-401: The ( n − 1) -dimensional spaces resulting from fixing a single coordinate of an n -dimensional coordinate system. The concept of a coordinate map , or coordinate chart is central to the theory of manifolds. A coordinate map is essentially a coordinate system for a subset of a given space with the property that each point has exactly one set of coordinates. More precisely, a coordinate map

4633-644: The Middle Ages , black has been the symbolic color of solemnity and authority, and for this reason it is still commonly worn by judges and magistrates. Black was one of the first colors used by artists in Neolithic cave paintings. It was used in ancient Egypt and Greece as the color of the underworld . In the Roman Empire , it became the color of mourning, and over the centuries it was frequently associated with death , evil, witches , and magic . In

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4746-517: The marten family, was the finest and most expensive fur in Europe. It was imported from Russia and Poland and used to trim the robes and gowns of royalty. In the 14th century, the status of black began to change. First, high-quality black dyes began to arrive on the market, allowing garments of a deep, rich black. Magistrates and government officials began to wear black robes, as a sign of the importance and seriousness of their positions. A third reason

4859-419: The pole and a ray from this point is taken as the polar axis . For a given angle θ , there is a single line through the pole whose angle with the polar axis is θ (measured counterclockwise from the axis to the line). Then there is a unique point on this line whose signed distance from the origin is r for given number r . For a given pair of coordinates ( r ,  θ ) there is a single point, but any point

4972-430: The 14th century, it was worn by royalty, clergy, judges, and government officials in much of Europe. It became the color worn by English romantic poets, businessmen and statesmen in the 19th century, and a high fashion color in the 20th century. According to surveys in Europe and North America, it is the color most commonly associated with mourning, the end, secrets, magic, force, violence, fear, evil, and elegance. Black

5085-580: The 4th century BC, where it was called masi . In India, the black color of the ink came from bone char , tar, pitch and other substances. The ancient Romans had a black writing ink they called atramentum librarium . Its name came from the Latin word atrare , which meant to make something black. (This was the same root as the English word atrocious .) It was usually made, like India ink, from soot, although one variety, called atramentum elephantinum ,

5198-505: The BT.709 gamut. The form of Y′CbCr that was defined for standard-definition television use in the ITU-R BT.601 (formerly CCIR 601 ) standard for use with digital component video is derived from the corresponding RGB space (ITU-R BT.470-6 System M primaries) as follows: From the above constants and formulas, the following can be derived for ITU-R BT.601. Analog YPbPr from analog R'G'B'

5311-430: The Cartesian coordinates of the point. This introduces an "extra" coordinate since only two are needed to specify a point on the plane, but this system is useful in that it represents any point on the projective plane without the use of infinity . In general, a homogeneous coordinate system is one where only the ratios of the coordinates are significant and not the actual values. Some other common coordinate systems are

5424-729: The Protestant Netherlands, Rembrandt used this sober new palette of blacks and browns to create portraits whose faces emerged from the shadows expressing the deepest human emotions. The Catholic painters of the Counter-Reformation, like Rubens , went in the opposite direction; they filled their paintings with bright and rich colors. The new Baroque churches of the Counter-Reformation were usually shining white inside and filled with statues, frescoes, marble, gold and colorful paintings, to appeal to

5537-475: The ancient Egyptians, black had positive associations; being the color of fertility and the rich black soil flooded by the Nile. It was the color of Anubis , the god of the underworld, who took the form of a black jackal , and offered protection against evil to the dead. To ancient Greeks, black represented the underworld, separated from the living by the river Acheron , whose water ran black. Those who had committed

5650-403: The artist would paint figures with a glossy clay slip on a red clay pot. When the pot was fired, the figures painted with the slip would turn black, against a red background. Later they reversed the process, painting the spaces between the figures with slip. This created magnificent red figures against a glossy black background. In the social hierarchy of ancient Rome , purple was reserved for

5763-520: The axes of the local system; they are the tips of three unit vectors aligned with those axes. The Earth as a whole is one of the most common geometric spaces requiring the precise measurement of location, and thus coordinate systems. Starting with the Greeks of the Hellenistic period , a variety of coordinate systems have been developed based on the types above, including: Black Black

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5876-419: The best radiative cooling, out of sunlight, is by using black paint, though it is important that it be black (a nearly perfect absorber) in the infrared as well. In elementary science, far ultraviolet light is called " black light " because, while itself unseen, it causes many minerals and other substances to fluoresce . Absorption of light is contrasted by transmission , reflection and diffusion , where

5989-617: The black-and-white information (see image example to the right). This is called chroma subsampling . YCbCr is sometimes abbreviated to YCC . Typically the terms Y′CbCr, YCbCr, YPbPr and YUV are used interchangeably, leading to some confusion. The main difference is that YPbPr is used with analog images and YCbCr with digital images, leading to different scaling values for U max and V max (in YCbCr both are 1 2 {\displaystyle {\tfrac {1}{2}}} ) when converting to/from YUV. Y′CbCr and YCbCr differ due to

6102-539: The century was designed by Hubert de Givenchy and was worn by Audrey Hepburn in the 1961 film Breakfast at Tiffany's . The American civil rights movement in the 1950s was a struggle for the political equality of African Americans . It developed into the Black Power movement in the early 1960s until the late 1980s, and the Black Lives Matter movement in the 2010s and 2020s. It also popularized

6215-451: The color red, worn by the pope and his cardinals, as the color of luxury, sin, and human folly. In some northern European cities, mobs attacked churches and cathedrals, smashed the stained glass windows and defaced the statues and decoration. In Protestant doctrine, clothing was required to be sober, simple and discreet. Bright colors were banished and replaced by blacks, browns and grays; women and children were recommended to wear white. In

6328-500: The color the subject of his most famous painting, Arrangement in grey and black number one (1871), better known as Whistler's Mother . Some 19th-century French painters had a low opinion of black: "Reject black," Paul Gauguin said, "and that mix of black and white they call gray. Nothing is black, nothing is gray." But Édouard Manet used blacks for their strength and dramatic effect. Manet's portrait of painter Berthe Morisot

6441-625: The constants are: This form of Y′CbCr is based on an RGB model that more closely fits the phosphor emission characteristics of newer CRTs and other modern display equipment. The conversion matrices for BT.709 are these: The definitions of the R', G', and B' signals also differ between BT.709 and BT.601, and differ within BT.601 depending on the type of TV system in use (625-line as in PAL and SECAM or 525-line as in NTSC ), and differ further in other specifications. In different designs there are differences in

6554-464: The darkest material is made from vertically aligned carbon nanotubes. The material was grown by MIT engineers and was reported to have a 99.995% absorption rate of any incoming light. This surpasses any former darkest materials including Vantablack , which has a peak absorption rate of 99.965% in the visible spectrum. The earliest pigments used by Neolithic man were charcoal , red ocher and yellow ocher . The black lines of cave art were drawn with

6667-444: The definition of the corresponding RGB space, and required to satisfy K R + K G + K B = 1 {\displaystyle K_{R}+K_{G}+K_{B}=1} . The equivalent matrix manipulation is often referred to as the "color matrix": And its inverse: Here, the prime (′) symbols mean gamma correction is being used; thus R′, G′ and B′ nominally range from 0 to 1, with 0 representing

6780-404: The definitions of the R, G, and B chromaticity coordinates, the reference white point, the supported gamut range, the exact gamma pre-compensation functions for deriving R', G' and B' from R, G, and B, and in the scaling and offsets to be applied during conversion from R'G'B' to Y′CbCr. So proper conversion of Y′CbCr from one form to the other is not just a matter of inverting one matrix and applying

6893-410: The development of fast SIMD floating-point processors, most digital implementations of RGB → Y′UV used integer math, in particular fixed-point approximations. Approximation means that the precision of the used numbers (input data, output data and constant values) is limited, and thus a precision loss of typically about the last binary digit is accepted by whoever makes use of that option in typically

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7006-433: The division. For studio-swing: Coordinate transformation In geometry , a coordinate system is a system that uses one or more numbers , or coordinates , to uniquely determine the position of the points or other geometric elements on a manifold such as Euclidean space . The order of the coordinates is significant, and they are sometimes identified by their position in an ordered tuple and sometimes by

7119-453: The dominant theme of romanticism. The novels of the period were filled with castles, ruins, dungeons, storms, and meetings at midnight. The leading poets of the movement were usually portrayed dressed in black, usually with a white shirt and open collar, and a scarf carelessly over their shoulder, Percy Bysshe Shelley and Lord Byron helped create the enduring stereotype of the romantic poet. The invention of inexpensive synthetic black dyes and

7232-469: The emperor; red was the color worn by soldiers (red cloaks for the officers, red tunics for the soldiers); white the color worn by the priests, and black was worn by craftsmen and artisans. The black they wore was not deep and rich; the vegetable dyes used to make black were not solid or lasting, so the blacks often faded to gray or brown. In Latin , the word for black, ater and to darken, atere , were associated with cruelty, brutality and evil. They were

7345-688: The end of the 16th century, it was the color worn by almost all the monarchs of Europe and their courts. While black was the color worn by the Catholic rulers of Europe, it was also the emblematic color of the Protestant Reformation in Europe and the Puritans in England and America. John Calvin , Philip Melanchthon and other Protestant theologians denounced the richly colored and decorated interiors of Roman Catholic churches. They saw

7458-429: The end of the 20th century, black was the emblematic color of the punk subculture punk fashion , and the goth subculture . Goth fashion, which emerged in England in the 1980s, was inspired by Victorian era mourning dress. In men's fashion, black gradually ceded its dominance to navy blue, particularly in business suits. Black evening dress and formal dress in general were worn less and less. In 1960, John F. Kennedy

7571-521: The end of the reign of King Richard II (1377–1399), where all the court began to wear black. In 1419–20, black became the color of the powerful Duke of Burgundy, Philip the Good . It moved to Spain, where it became the color of the Spanish Habsburgs, of Charles V and of his son, Philip II of Spain (1527–1598). European rulers saw it as the color of power, dignity, humility and temperance. By

7684-466: The fashion capital, and pastels, blues, greens, yellow and white became the colors of the nobility and upper classes. But after the French Revolution , black again became the dominant color. Black was the color of the industrial revolution, largely fueled by coal, and later by oil. Thanks to coal smoke , the buildings of the large cities of Europe and America gradually turned black . By 1846

7797-435: The following: There are ways of describing curves without coordinates, using intrinsic equations that use invariant quantities such as curvature and arc length . These include: Coordinates systems are often used to specify the position of a point, but they may also be used to specify the position of more complex figures such as lines, planes, circles or spheres . For example, Plücker coordinates are used to determine

7910-478: The footroom offset 16 needs to be subtracted first from each signal, and a scale factor of 255 219 {\displaystyle {\frac {255}{219}}} needs to be included in the equations. The inverse transform is: The inverse transform without any roundings (using values coming directly from ITU-R BT.601 recommendation) is: This form of Y′CbCr is used primarily for older standard-definition television systems, as it uses an RGB model that fits

8023-577: The fraction (235-16)/(240-16) = 219/224 is sometimes required when doing color matrixing or processing in YCbCr space, resulting in quantization distortions when the subsequent processing is not performed using higher bit depths. The scaling that results in the use of a smaller range of digital values than what might appear to be desirable for representation of the nominal range of the input data allows for some "overshoot" and "undershoot" during processing without necessitating undesirable clipping . This " headroom " and "toeroom" can also be used for extension of

8136-418: The full range with zero representing black and 255 representing white) according to the following equations: In the formula below, the scaling factors are multiplied by 256 255 {\displaystyle {\frac {256}{255}}} . This allows for the value 256 in the denominator, which can be calculated by a single bitshift . If the R'd G'd B'd digital source includes footroom and headroom,

8249-490: The greatest contrast with white paper or parchment, making it the easiest color to read. It became even more important in the 15th century, with the invention of printing . A new kind of ink, printer's ink, was created out of soot , turpentine and walnut oil . The new ink made it possible to spread ideas to a mass audience through printed books, and to popularize art through black and white prints. Because of its contrast and clarity, black ink on white paper continued to be

8362-534: The industrial area of the West Midlands of England was "commonly called 'the Black Country '". Charles Dickens and other writers described the dark streets and smoky skies of London, and they were vividly illustrated in the wood-engravings of French artist Gustave Doré . A different kind of black was an important part of the romantic movement in literature. Black was the color of melancholy ,

8475-484: The industrialization of the textile industry meant that high-quality black clothes were available for the first time to the general population. In the 19th century black gradually became the most popular color of business dress of the upper and middle classes in England, the Continent, and America. Black dominated literature and fashion in the 19th century, and played a large role in painting. James McNeill Whistler made

8588-553: The light is only redirected, causing objects to appear transparent, reflective or white respectively. A material is said to be black if most incoming light is absorbed equally in the material. Light ( electromagnetic radiation in the visible spectrum ) interacts with the atoms and molecules , which causes the energy of the light to be converted into other forms of energy, usually heat. This means that black surfaces can act as thermal collectors, absorbing light and generating heat (see Solar thermal collector ). As of September 2019,

8701-405: The middle of the 14th century. The most common early dyes were made from bark, roots or fruits of different trees; usually walnuts, chestnuts, or certain oak trees. The blacks produced were often more gray, brown or bluish. The cloth had to be dyed several times to darken the color. One solution used by dyers was add to the dye some iron filings, rich in iron oxide, which gave a deeper black. Another

8814-419: The minimum intensity (e.g., for display of the color black ) and 1 the maximum (e.g., for display of the color white ). The resulting luma (Y) value will then have a nominal range from 0 to 1, and the chroma (P B and P R ) values will have a nominal range from -0.5 to +0.5. The reverse conversion process can be readily derived by inverting the above equations. When representing the signals in digital form,

8927-485: The modern inkstick have been found dating to about 256 BC at the end of the Warring States period . They were produced from soot , usually produced by burning pine wood, mixed with animal glue . To make ink from an inkstick, the stick is continuously ground against an inkstone with a small quantity of water to produce a dark liquid which is then applied with an ink brush . Artists and calligraphists could vary

9040-516: The most expensive fabrics. The change to the more austere but elegant black was quickly picked up by the kings and nobility. It began in northern Italy, where the Duke of Milan and the Count of Savoy and the rulers of Mantua, Ferrara, Rimini and Urbino began to dress in black. It then spread to France, led by Louis I, Duke of Orleans , younger brother of King Charles VI of France . It moved to England at

9153-512: The nominal color gamut , as specified by xvYCC . The value 235 accommodates a maximum overshoot of (255 - 235) / (235 - 16) = 9.1%, which is slightly larger than the theoretical maximum overshoot ( Gibbs' Phenomenon ) of about 8.9% of the maximum (black-to-white) step. The toeroom is smaller, allowing only 16 / 219 = 7.3% overshoot, which is less than the theoretical maximum overshoot of 8.9%. In addition, because values 0 and 255 are reserved in HDMI,

9266-526: The notorious Salem witch trials in New England in 1692–93, one of those on trial was accused of being able turn into a "black thing with a blue cap," and others of having familiars in the form of a black dog, a black cat and a black bird. Nineteen women and men were hanged as witches. In the 18th century, during the European Age of Enlightenment , black receded as a fashion color. Paris became

9379-453: The other two are allowed to vary, then the resulting surface is called a coordinate surface . For example, the coordinate surfaces obtained by holding ρ constant in the spherical coordinate system are the spheres with center at the origin. In three-dimensional space the intersection of two coordinate surfaces is a coordinate curve. In the Cartesian coordinate system we may speak of coordinate planes . Similarly, coordinate hypersurfaces are

9492-468: The other. In fact, when Y′CbCr is designed ideally, the values of K B and K R are derived from the precise specification of the RGB color primary signals, so that the luma (Y′) signal corresponds as closely as possible to a gamma-adjusted measurement of luminance (typically based on the CIE 1931 measurements of the response of the human visual system to color stimuli). The ITU-R BT.2020 standard uses

9605-477: The phosphor emission characteristics of older CRTs. A different form of Y′CbCr is specified in the ITU-R BT.709 standard, primarily for HDTV use. The newer form is also used in some computer-display oriented applications, as sRGB (though the matrix used for sRGB form of YCbCr, sYCC , is still BT.601). In this case, the values of Kb and Kr differ, but the formulas for using them are the same. For ITU-R BT.709,

9718-408: The position of a line in space. When there is a need, the type of figure being described is used to distinguish the type of coordinate system, for example the term line coordinates is used for any coordinate system that specifies the position of a line. It may occur that systems of coordinates for two different sets of geometric figures are equivalent in terms of their analysis. An example of this

9831-413: The public. But European Catholics of all classes, like Protestants, eventually adopted a sober wardrobe that was mostly black, brown and gray. In the second part of the 17th century, Europe and America experienced an epidemic of fear of witchcraft . People widely believed that the devil appeared at midnight in a ceremony called a Black Mass or black sabbath, usually in the form of a black animal, often

9944-418: The result reflects so little light as to be called black. This provides two superficially opposite but actually complementary descriptions of black. Black is the color produced by the absorption of all wavelengths of visible light, or an exhaustive combination of multiple colors of pigment. In physics, a black body is a perfect absorber of light, but, by a thermodynamic rule, it is also the best emitter. Thus,

10057-449: The results are scaled and rounded, and offsets are typically added. For example, the scaling and offset applied to the Y′ component per specification (e.g. MPEG-2 ) results in the value of 16 for black and the value of 235 for white when using an 8-bit representation. The standard has 8-bit digitized versions of C B and C R scaled to a different range of 16 to 240. Consequently, rescaling by

10170-535: The room is actually slightly less. Since the equations defining Y′CbCr are formed in a way that rotates the entire nominal RGB color cube and scales it to fit within a (larger) YCbCr color cube, there are some points within the Y′CbCr color cube that cannot be represented in the corresponding RGB domain (at least not within the nominal RGB range). This causes some difficulty in determining how to correctly interpret and display some Y′CbCr signals. These out-of-range Y′CbCr values are used by xvYCC to encode colors outside

10283-526: The root of the English words "atrocious" and "atrocity". For the Romans, black symbolized death and mourning. In the 2nd century BC Roman magistrates wore a dark toga, called a toga pulla , to funeral ceremonies. Later, under the Empire, the family of the deceased also wore dark colors for a long period; then, after a banquet to mark the end of mourning, exchanged the black for a white toga. In Roman poetry, death

10396-713: The same gamma function as BT.709. It defines: For both, the coefficients derived from the primaries are: For NCL, the definition is classical: Y ′ = 0.2627 R ′ + 0.6780 G ′ + 0.0593 B ′ {\displaystyle Y'=0.2627R'+0.6780G'+0.0593B'} ; C b = ( B ′ − Y ′ ) / 1.8814 {\displaystyle Cb=(B'-Y')/1.8814} ; C r = ( R ′ − Y ′ ) / 1.4746 {\displaystyle Cr=(R'-Y')/1.4746} . The encoding conversion can, as usual, be written as

10509-617: The same word to name different colors, if they had the same intensity. Kuanos' could mean both dark blue and black. The Ancient Romans had two words for black: ater was a flat, dull black, while niger was a brilliant, saturated black. Ater has vanished from the vocabulary, but niger was the source of the country name Nigeria, the English word Negro , and the word for "black" in most modern Romance languages ( French : noir ; Spanish and Portuguese : negro ; Italian : nero ; Romanian : negru ). Old High German also had two words for black: swartz for dull black and blach for

10622-526: The slogan " Black is Beautiful ". In the visible spectrum , black is the result of the absorption of all light wavelengths. Black can be defined as the visual impression (or color) experienced when no visible light reaches the eye. Pigments or dyes that absorb light rather than reflect it back to the eye look black. A black pigment can, however, result from a combination of several pigments that collectively absorb all wavelengths of visible light. If appropriate proportions of three primary pigments are mixed,

10735-399: The space to itself two coordinate transformations can be associated: For example, in 1D , if the mapping is a translation of 3 to the right, the first moves the origin from 0 to 3, so that the coordinate of each point becomes 3 less, while the second moves the origin from 0 to −3, so that the coordinate of each point becomes 3 more. Given a coordinate system, if one of the coordinates of

10848-442: The standard for printing books, newspapers and documents; and for the same reason black text on a white background is the most common format used on computer screens. In the early Middle Ages, princes, nobles and the wealthy usually wore bright colors, particularly scarlet cloaks from Italy. Black was rarely part of the wardrobe of a noble family. The one exception was the fur of the sable . This glossy black fur, from an animal of

10961-624: The thickness of the resulting ink by reducing or increasing the intensity and time of ink grinding. These inks produced the delicate shading and subtle or dramatic effects of Chinese brush painting . India ink (or "Indian ink" in British English ) is a black ink once widely used for writing and printing and now more commonly used for drawing, especially when inking comic books and comic strips. The technique of making it probably came from China. India ink has been in use in India since at least

11074-471: The tips of burnt torches made of a wood with resin . Different charcoal pigments were made by burning different woods and animal products, each of which produced a different tone. The charcoal would be ground and then mixed with animal fat to make the pigment. The 15th-century painter Cennino Cennini described how this pigment was made during the Renaissance in his famous handbook for artists: "...there

11187-485: The values being gamma corrected or not. The equations below give a better picture of the common principles and general differences between these formats. Y′CbCr signals (prior to scaling and offsets to place the signals into digital form) are called YPbPr , and are created from the corresponding gamma-adjusted RGB (red, green and blue) source using three defined constants K R , K G , and K B as follows: where K R , K G , and K B are ordinarily derived from

11300-619: The virtues". Black symbolized both power and secrecy in the medieval world. The emblem of the Holy Roman Empire of Germany was a black eagle. The black knight in the poetry of the Middle Ages was an enigmatic figure, hiding his identity, usually wrapped in secrecy. Black ink , invented in China, was traditionally used in the Middle Ages for writing, for the simple reason that black was the darkest color and therefore provided

11413-473: The word used for the black color is sable , named for the black fur of the sable , an animal. Black was one of the first colors used in art. The Lascaux Cave in France contains drawings of bulls and other animals drawn by paleolithic artists between 18,000 and 17,000 years ago. They began by using charcoal, and later achieved darker pigments by burning bones or grinding a powder of manganese oxide . For

11526-414: The world for him, watching and listening. In the early Middle Ages, black was commonly associated with darkness and evil. In Medieval paintings, the devil was usually depicted as having human form, but with wings and black skin or hair. In fashion, black did not have the prestige of red, the color of the nobility. It was worn by Benedictine monks as a sign of humility and penitence. In the 12th century

11639-418: The worst sins were sent to Tartarus , the deepest and darkest level. In the center was the palace of Hades , the king of the underworld, where he was seated upon a black ebony throne. Black was one of the most important colors used by ancient Greek artists. In the 6th century BC, they began making black-figure pottery and later red figure pottery , using a highly original technique. In black-figure pottery,

11752-499: Was a study in black which perfectly captured her spirit of independence. The black gave the painting power and immediacy; he even changed her eyes, which were green, to black to strengthen the effect. Henri Matisse quoted the French impressionist Pissarro telling him, "Manet is stronger than us all – he made light with black." Pierre-Auguste Renoir used luminous blacks, especially in his portraits. When someone told him that black

11865-535: Was called the hora nigra , the black hour. The German and Scandinavian peoples worshipped their own goddess of the night, Nótt , who crossed the sky in a chariot drawn by a black horse. They also feared Hel , the goddess of the kingdom of the dead, whose skin was black on one side and red on the other. They also held sacred the raven . They believed that Odin , the king of the Nordic pantheon, had two black ravens, Huginn and Muninn, who served as his agents, traveling

11978-399: Was made by burning the ivory of elephants. Gall-nuts were also used for making fine black writing ink. Iron gall ink (also known as iron gall nut ink or oak gall ink) was a purple-black or brown-black ink made from iron salts and tannic acids from gall nut. It was the standard writing and drawing ink in Europe, from about the 12th century to the 19th century, and remained in use well into

12091-463: Was not a color, Renoir replied: "What makes you think that? Black is the queen of colors. I always detested Prussian blue. I tried to replace black with a mixture of red and blue, I tried using cobalt blue or ultramarine, but I always came back to ivory black." Vincent van Gogh used black lines to outline many of the objects in his paintings, such as the bed in the famous painting of his bedroom. making them stand apart. His painting of black crows over

12204-409: Was not derived from primaries, but now Netflix allows BT.2020 primaries (since 2021). The same happens with JPEG: it has BT.601 matrix derived from System M primaries, yet the primaries of most images are BT.709. Cathode-ray tube (CRT) displays are driven by red, green, and blue voltage signals, but these RGB signals are not efficient as a representation for storage and transmission, since they have

12317-468: Was the last American President to be inaugurated wearing formal dress; Lyndon Johnson and his successors were inaugurated wearing business suits. Women's fashion was revolutionized and simplified in 1926 by the French designer Coco Chanel , who published a drawing of a simple black dress in Vogue magazine. She famously said, "A woman needs just three things; a black dress, a black sweater, and, on her arm,

12430-402: Was the passage of sumptuary laws in some parts of Europe which prohibited the wearing of costly clothes and certain colors by anyone except members of the nobility. The famous bright scarlet cloaks from Venice and the peacock blue fabrics from Florence were restricted to the nobility. The wealthy bankers and merchants of northern Italy responded by changing to black robes and gowns, made with

12543-402: Was to first dye the fabric dark blue, and then to dye it black. A much richer and deeper black dye was eventually found made from the oak apple or "gall-nut". The gall-nut is a small round tumor which grows on oak and other varieties of trees. They range in size from 2–5 cm, and are caused by chemicals injected by the larva of certain kinds of gall wasp in the family Cynipidae. The dye

12656-495: Was very expensive; a great quantity of gall-nuts were needed for a very small amount of dye. The gall-nuts which made the best dye came from Poland, eastern Europe, the near east and North Africa. Beginning in about the 14th century, dye from gall-nuts was used for clothes of the kings and princes of Europe. Another important source of natural black dyes from the 17th century onwards was the logwood tree , or Haematoxylum campechianum , which also produced reddish and bluish dyes. It

12769-641: Was worn by Left-Bank intellectuals and performers such as Juliette Gréco , and by some members of the Beat Movement in New York and San Francisco. Black leather jackets were worn by motorcycle gangs such as the Hells Angels and street gangs on the fringes of society in the United States. Black as a color of rebellion was celebrated in such films as The Wild One , with Marlon Brando . By

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