j经典ava论文论文模板

Primary colors are sets of colors that can be combined to make a useful range of colors. For human applications, three primary colors are usually used, since human color vision is additive combination of colors, as in overlapping projected lights or in CRT displays, the primary colors normally used are red, green, and blue. For subtractive combination of colors, as in mixing of pigments or dyes, such as in printing, the primaries normally used are cyan, magenta, and yellow,[1] though the set of red, yellow, blue is popular among artists.[2] See RGB color model, CMYK color model, and RYB color model for more on these popular sets of primary choice of primary colors is essentially arbitrary; for example, an early color photographic process, autochrome, typically used orange, green, and violet primaries.[3]The most commonly used additive color primaries are the secondary colors of the most commonly used subtractive color primaries, and vice colors are not a fundamental property of light but are often related to the physiological response of the eye to light. Fundamentally, light is a continuous spectrum of the wavelengths that can be detected by the human eye, an infinite-dimensional stimulus space.[4] However, the human eye normally contains only three types of color receptors, called cone cells. Each color receptor responds to different ranges of the color spectrum. Humans and other species with three such types of color receptors are known as trichromats. These species respond to the light stimulus via a three-dimensional sensation, which generally can be modeled as a mixture of three primary colors.[4]Before the nature of colorimetry and visual physiology were well understood, scientists such as Thomas Young, James Clark Maxwell, and Hermann von Helmholtz expressed various opinions about what should be the three primary colors to describe the three primary color sensations of the eye.[5] Young originally proposed red, green, and violet, and Maxwell changed violet to blue; Helmholtz proposed "a slightly purplish red, a vegetation-green, slightly yellowish (wave-length about 5600 tenth-metres), and an ultramarine-blue (about 4820)".[6] In modern understanding, the human cone cells do not correspond to any real primary with different numbers of receptor cell types would have color vision requiring a different number of primaries. For example, for species known as tetrachromats, with four different color receptors, one would use four primary colors. Since humans can only see to 400 nanometers (violet), but tetrachromats can see into the ultraviolet to about 300 nanometers, this fourth primary color might be located in the shorter-wavelength birds and marsupials are tetrachromats, and it has been suggested that some human females are tetrachromats as well[7][8], having an extra variant version of the long-wave (L) cone type.[9] The peak response of human color receptors varies, even among individuals with "normal" color vision[10]; in non-human species this polymorphic variation is even greater, and it may well be adaptive[11]. Most mammals other than primates have only two types of color receptors and are therefore dichromats; to them, there are only two primary would be incorrect to assume that the world "looks tinted" to an animal (or human) with anything other than the human standard of three color receptors. To an animal (or human) born that way, the world would look normal to it, but the animal's ability to detect and discriminate colors would be different from that of a human with normal color vision. If a human and an animal both look at a natural color, they see it as natural; however, if both look at a color reproduced via primary colors, such as on a color television screen, the human may see it as matching the natural color, while the animal does not; in this sense, reproduction of color via primaries must be "tuned" to the color vision system of the that combine emitted lights to create the sensation of a range of colors are using the additive color system. Typically, the primary colors used are red, green, and blue.[12]Television and other computer and video displays are a common example of the use of additive primaries and the RGB color model. The exact colors chosen for the primaries are a technological compromise between the available phosphors (including considerations such as cost and power usage) and the need for large color triangle to allow a large gamut of colors. The ITU-R primaries are 1931 RGB color triangle with monochromatic primariesAdditive mixing of red and green light produces shades of yellow, orange, or brown.[13] Mixing green and blue produces shades of cyan, and mixing red and blue produces shades of purple, including magenta. Mixing nominally equal proportions of the additive primaries results in shades of grey or white; the color space that is generated is called an RGB color CIE 1931 color space defines monochromatic primary colors with wavelengths of nm (violet), nm (green) and 700 nm (red). The corners of the color triangle are therefore on the spectral locus, and the triangle is about as big as it can be. No real display device uses such primaries, as the extreme wavelengths used for violet and red result in a very low luminous article: RYB color modelRYB (red, yellow, and blue) is a historical set of subtractive primary colors. It is primarily used in art and art education, particularly painting.[14] It predates modern scientific color RYB Color WheelRYB make up the primary color triad in a standard color wheel; the secondary colors VOG (violet, orange, and green) make up another triad. Triads are formed by 3 equidistant colors on a particular color wheel; neither RYB nor VOG is equidistant on a perceptually uniform color wheel, but rather have been defined to be equidistant in the RYB wheel.[15]Painters have long used more than three "primary" colors in their palettes—and at one point considered red, yellow, blue, and green to be the four primaries[16]. Red, yellow, blue, and green are still widely considered the four psychological primary colors,[17] though red, yellow, and blue are sometimes listed as the three psychological primaries [18], with black and white occasionally added as a fourth and fifth [19].During the 18th century, as theorists became aware of Isaac Newton’s scientific experiments with light and prisms, red, yellow, and blue became the canonical primary colors—supposedly the fundamental sensory qualities that are blended in the perception of all physical colors and equally in the physical mixture of pigments or dyes. This theory became dogma, despite abundant evidence that red, yellow, and blue primaries cannot mix all other colors, and has survived in color theory to the present day.[20]Using red, yellow, and blue as primaries yields a relatively small gamut, in which, among other problems, colorful greens, cyans, and magentas are impossible to mix, because red, yellow, and blue are not well-spaced around a perceptually uniform color wheel. For this reason, modern three- or four-color printing processes, as well as color photography, use cyan, yellow, and magenta as primaries instead.[21] Most painters include colors in their palettes which cannot be mixed from yellow, red, and blue paints, and thus do not fit within the RYB color model. Some who do use a three-color palette opt for the more evenly spaced cyan, yellow, and magenta used by printers, and others paint with 6 or more colors to widen their gamuts.[22] The cyan, magenta, and yellow used in printing are sometimes known as "process blue," "process red," "process yellow."[23][edit] CMYK color model, or four-color printingMain article: CMYK color modelIn the printing industry, to produce the varying colors the subtractive primaries cyan, magenta, and yellow are applied together in varying amounts. Before the color names cyan and magenta were in common use, these primaries were often known as blue-green and purple, or in some circles as blue and red, respectively, and their exact color has changed over time with access to new pigments and technologies.[24]Subtractive color mixing – the magenta and cyan primaries are sometimes called purple and blue-green, or red and blueMixing yellow and cyan produces green colors; mixing yellow with magenta produces reds, and mixing magenta with cyan produces blues. In theory, mixing equal amounts of all three pigments should produce grey, resulting in black when all three are applied in sufficient density, but in practice they tend to produce muddy brown colors. For this reason, and to save ink and decrease drying times, a fourth pigment, black, is often used in addition to cyan, magenta, and resulting model is the so-called CMYK color model. The abbreviation stands for cyan, magenta, yellow, and key—black is referred to as the key color, a shorthand for the key printing plate that impressed the artistic detail of an image, usually in black ink.[25]In practice, colorant mixtures in actual materials such as paint tend to be more complex. Brighter or more saturated colors can be created using natural pigments instead of mixing, and natural properties of pigments can interfere with the mixing. For example, mixing magenta and green in acrylic creates a dark cyan—something which would not happen if the mixing process were perfectly the subtractive model, adding white to a color, whether by using less colorant or by mixing in a reflective white pigment such as zinc oxide, does not change the color’s hue but does reduce its saturation. Subtractive color printing works best when the surface or paper is white, or close to system of subtractive color does not have a simple chromaticity gamut analogous to the RGB color triangle, but a gamut that must be described in three dimensions. There are many ways to visualize such models, using various 2D chromaticity spaces or in 3D color spacesNotes and references^ Matthew Luckiesh (1915). Color and Its Applications. D. Van Nostrand company. pp. 58, 221. . ^ Chris Grimley and Mimi Love (2007). Color, space, and style: all the details interior designers need to know but can never find. Rockport Publishers. p. 137. ISBN 9781592532278. . ^ Walter Hines Page and Arthur Wilson Page (1908). The World's Work: Volume XV: A History of Our Time. Doubleday, Page & Company. . ^ a b Michael I. Sobel (1989). Light. University of Chicago Press. pp. 52–62. ISBN 0226767515. . ^ Edward Albert Sharpey-Schäfer (1900). Text-book of physiology. 2. Y. J. Pentland. p. 1107. . ^ Alfred Daniell (1904). A text book of the principles of physics. Macmillan and Co. p. 575. . ^ Backhaus, Kliegl & Werner "Color vision, perspectives from different disciplines" (De Gruyter, 1998), , section . ^ Pr. Mollon (Cambridge university), Pr. Jordan (Newcastle university) "Study of women heterozygote for colour difficiency" (Vision Research, 1993) ^ M. Neitz, T. W. Kraft, and J. Neitz (1998). "Expression of L cone pigment gene subtypes in females". Vision Research 38: 3221–3225. doi:(98)00076-5. ^ Neitz, Jay & Jacobs, Gerald H. (1986). "Polymorphism of the long-wavelength cone in normal human colour vision." Nature. 323, 623-625. ^ Jacobs, Gerald H. (1996). "Primate photopigments and primate color vision." PNAS. 93 (2), 577–581. ^ Thomas D. Rossing and Christopher J. Chiaverina (1999). Light science: physics and the visual arts. Birkhäuser. p. 178. ISBN 9780387988276. . ^ "Some Experiments on Color", Nature 111, 1871, in John William Strutt (Lord Rayleigh) (1899). Scientific Papers. University Press. . ^ Tom Fraser and Adam Banks (2004). Designer’s Color Manual: The Complete Guide to Color Theory and Application. Chronicle Books. ISBN 081184210X. . ^ Stephen Quiller (2002). Color Choices. Watson–Guptill. ISBN 0823006972. . ^ For instance Leonardo da Vinci wrote of these four simple colors in his notebook circa 1500. See Rolf Kuenhi. “Development of the Idea of Simple Colors in the 16th and Early 17th Centuries”. Color Research and Application. Volume 32, Number 2, April 2007. ^ Resultby Leslie D. Stroebel, Ira B. Current (2000). Basic Photographic Materials and Processes. Focal Press. ISBN 0240803450. . ^ MS Sharon Ross , Elise Kinkead (2004). Decorative Painting & Faux Finishes. Creative Homeowner. ISBN 1580111793. . ^ Swirnoff, Lois (2003). Dimensional Color. W. W. Norton & Company. ISBN 0393731022. . ^ Bruce MacEvoy. “Do ‘Primary’ Colors Exist?” (Material Trichromacy section). Handprint. Accessed 10 August 2007. ^ “Development of the Idea of Simple Colors in the 16th and Early 17th Centuries”. Color Research and Application. Volume 32, Number 2, April 2007. ^ Bruce MacEvoy. “Secondary Palette.” Handprint. Accessed 14 August 2007. For general discussion see Bruce MacEvoy. “Mixing With a Color Wheel” (Saturation Costs section). Handprint. Accessed 14 August 2007. ^ Cheap Brochure Printing - Process Blue / Process Red / Process Yellow / Process Black ^ Ervin Sidney Ferry (1921). General Physics and Its Application to Industry and Everyday Life. John Wiley & Sons. . ^ Frank S. Henry (1917). Printing for School and Shop: A Textbook for Printers' Apprentices, Continuation Classes, and for General use in Schools. John Wiley & Sons. . ^ See the google image results for “cmyk gamut” for examples. 不知这个可不可以当做论文