|
HSV Color Space
HSL and HSV are the two most common cylindrical-coordinate representations of points in an RGB color model. The two representations rearrange the geometry of RGB in an attempt to be more intuitive and perceptually relevant than the cartesian (cube) representation. Developed in the 1970s for computer graphics applications, HSL and HSV are used today in color pickers, in image editing software, and less commonly in image analysis and computer vision. HSL stands for ''hue'', ''saturation'', and ''lightness'', and is often also called HLS. HSV stands for ''hue'', ''saturation'', and ''value'', and is also often called HSB (''B'' for ''brightness''). A third model, common in computer vision applications, is HSI, for ''hue'', ''saturation'', and ''intensity''. However, while typically consistent, these definitions are not standardized, and any of these abbreviations might be used for any of these three or several other related cylindrical models. (For technical definitions of these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CIELAB
The CIELAB color space, also referred to as ''L*a*b*'', is a color space defined by the International Commission on Illumination (abbreviated CIE) in 1976. It expresses color as three values: ''L*'' for perceptual lightness and ''a*'' and ''b*'' for the four Unique hues, unique colors of human vision: red, green, blue and yellow. CIELAB was intended as a perceptually uniform space, where a given numerical change corresponds to a similar perceived change in color. While the LAB space is not truly perceptually uniform, it nevertheless is useful in industry for detecting small differences in color. Like the CIE 1931 color space, CIEXYZ space it derives from, CIELAB color space is a device-independent, "standard observer" model. The colors it defines are not relative to any particular device such as a computer monitor or a printer, but instead relate to the CIE 1931 color space#CIE standard observer, CIE standard observer which is an averaging of the results of color matching expe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorfulness
Colorfulness, chroma and saturation are attributes of perceived color relating to chromatic intensity. As defined formally by the International Commission on Illumination (CIE) they respectively describe three different aspects of chromatic intensity, but the terms are often used loosely and interchangeably in contexts where these aspects are not clearly distinguished. The precise meanings of the terms vary by what other functions they are dependent on. * Colorfulness is the "attribute of a visual perception according to which the perceived color of an area appears to be more or less chromatic (Any color that is absent of white, grey, or black)"., page 87. The colorfulness evoked by an object depends not only on its spectral reflectance but also on the strength of the illumination, and increases with the latter unless the brightness is very high (Hunt effect (color), Hunt effect). * Chroma is the "colorfulness of an area judged as a proportion of the brightness of a similarl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cone
In geometry, a cone is a three-dimensional figure that tapers smoothly from a flat base (typically a circle) to a point not contained in the base, called the '' apex'' or '' vertex''. A cone is formed by a set of line segments, half-lines, or lines connecting a common point, the apex, to all of the points on a base. In the case of line segments, the cone does not extend beyond the base, while in the case of half-lines, it extends infinitely far. In the case of lines, the cone extends infinitely far in both directions from the apex, in which case it is sometimes called a ''double cone''. Each of the two halves of a double cone split at the apex is called a ''nappe''. Depending on the author, the base may be restricted to a circle, any one-dimensional quadratic form in the plane, any closed one-dimensional figure, or any of the above plus all the enclosed points. If the enclosed points are included in the base, the cone is a solid object; otherwise it is an open surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicone
In geometry, a bicone or dicone (from , and Greek: ''di-'', both meaning "two") is the three-dimensional surface of revolution of a rhombus around one of its axes of symmetry. Equivalently, a bicone is the surface created by joining two congruent right circular cones at their bases. A bicone has circular symmetry and orthogonal bilateral symmetry. Geometry For a bicone with radius r and half-height h, the volume is :V = \frac \pi r^2 h and the surface area is :A =2\pi r \ell\, where :\ell = \sqrt is the slant height. See also * Sphericon In solid geometry, the sphericon is a solid that has a continuous developable surface with two Congruence (geometry), congruent, semicircle, semi-circular edges, and four Vertex (geometry), vertices that define a square. It is a member of a spe ... * Biconical antenna References External links * Elementary geometry Surfaces {{Elementary-geometry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Range (statistics)
In descriptive statistics, the range of a set of data is size of the narrowest interval which contains all the data. It is calculated as the difference between the largest and smallest values (also known as the sample maximum and minimum). It is expressed in the same units as the data. The range provides an indication of statistical dispersion. Closely related alternative measures are the Interdecile range and the Interquartile range. Range of continuous IID random variables For ''n'' independent and identically distributed continuous random variables ''X''1, ''X''2, ..., ''X''''n'' with the cumulative distribution function G(''x'') and a probability density function g(''x''), let T denote the range of them, that is, T= max(''X''1, ''X''2, ..., ''X''''n'')- min(''X''1, ''X''2, ..., ''X''''n''). Distribution The range, T, has the cumulative distribution function ::F(t)= n \int_^\infty g(x) (x+t)-G(x) \, \textx. Gumbel notes that the "beauty of this formula is com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tints And Shades
In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness. A tone is produced either by mixing a color with gray, or by both tinting and shading. Mixing a color with any neutral color (black, gray, and white) reduces the chroma, or colorfulness, while the perceived hue can be affected slightly (see Abney effect and Bezold-Brücke shift). In the graphic arts, especially printmaking and drawing, "tone" has a different meaning, referring to areas of continuous color, produced by various means, as opposed to the linear marks made by an engraved or drawn line. In common language, the term ''shade'' can be generalized to encompass any varieties of a particular color, whether technically they are shades, tints, tones, or slightly different hues. Meanwhile, the term ''tint'' can be generalized to refer to any lighter or darker variation of a color (e.g. " tinted windows"). When mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magenta
Magenta () is a purple-red color. On color wheels of the RGB color model, RGB (additive) and subtractive color, CMY (subtractive) color models, it is located precisely midway between blue and red. It is one of the four colors of ink used in color printing by most Color printing, color printers, along with yellow, cyan, and black to make all the other colors. Magenta is a color made by mixing red and blue. The tone of magenta used in printing, Shades of magenta, printer's magenta, is redder than the magenta of the RGB (additive) model, the former being closer to Rose (color), rose. Magenta took its name from an aniline dye made and patented in 1859 by the French chemist François-Emmanuel Verguin, who originally called it ''fuchsine''. It was renamed to celebrate the French-Sardinian victory under French Emperor Napoleon III at the Battle of Magenta against the larger army of the Austrian Empire on 4 June 1859 near the Italian town of Magenta, Lombardy, Magenta, at the time in Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyan
Cyan () is the color between blue and green on the visible spectrum of light. It is evoked by light with a predominant wavelength between 500 and 520 nm, between the wavelengths of green and blue. In the subtractive color system, or CMYK color model, which can be overlaid to produce all colors in paint and color printing, cyan is one of the primary colors, along with magenta and yellow. In the additive color system, or RGB color model, used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light. Cyan is the complement of red; it can be made by the removal of red from white. Mixing red light and cyan light at the right intensity will make white light. It is commonly seen on a bright, sunny day in the sky. Shades and variations Different shades of cyan can vary in terms of hue, chroma (also known as saturation, intensity, or colorfulness), or lightness (or value, tone, or brightness), or any combinat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow
Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the RGB color model, used to create colors on television and computer screens, yellow is a secondary color made by combining red and green at equal intensity. Carotenoids give the characteristic yellow color to autumn leaves, corn, canaries, daffodils, and lemons, as well as egg yolks, buttercups, and bananas. They absorb light energy and protect plants from photo damage in some cases. Sunlight has a slight yellowish hue when the Sun is near the horizon, due to atmospheric scattering of shorter wavelengths (green, blue, and violet). Because it was widely available, yellow ochre pigment was one of the first colors used in art; the Lascaux cave in France has a painting of a yellow horse 17,000 years old. Ochre and orpiment pigmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Color
A secondary color is a color made by color mixing, mixing two primary colors of a given color model in even proportions. Combining two secondary colors in the same manner produces a tertiary color. Secondary colors are special in traditional color theory, but have no special meaning in color science. Overview Primary color In traditional color theory, it is believed that all colors can be mixed from 3 universal primary - or pure - colors, which were originally believed to be red, yellow and blue pigments (representing the RYB color model). However, modern color science does not recognize universal primary colors and only defines primary colors for a given color model or color space. RGB color model, RGB and CMYK color model, CMYK color models are popular color models in modern color science, but are only chosen as efficient primaries, in that their combination leads to a large gamut. However, any three primaries can produce a viable color gamut. The RYB model continues to be us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Additive Color
Additive color or additive mixing is a property of a color model that predicts the appearance of colors made by coincident component lights, i.e. the perceived color can be predicted by summing the numeric representations of the component colors. Modern formulations of Grassmann's laws describe the additivity in the color perception of light mixtures in terms of algebraic equations. Additive color predicts perception and not any sort of change in the photons of light themselves. These predictions are only applicable in the limited scope of color matching experiments where viewers match small patches of uniform color isolated against a gray or black background. Additive color models are applied in the design and testing of electronic displays that are used to render realistic images containing diverse sets of color using phosphors that emit light of a limited set of primary colors. Examination with a sufficiently powerful magnifying lens will reveal that each pixel in CRT, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
