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Unique Hues
Unique hue is a term used in perceptual psychology of color vision and generally applied to the purest hues of blue, green, yellow and red. The proponents of the opponent process theory believe that these hues cannot be described as a mixture of other hues, and are therefore pure, whereas all other hues are composite. The neural correlate of the unique hues are approximated by the extremes of the opponent channels in opponent process theory. In this context, unique hues are sometimes described as " psychological primaries" as they can be considered analogous to the primary colors of trichromatic color theory. Opponent process theory The concept of certain hues as 'unique' came with the introduction of opponent process theory, which Ewald Hering introduced in 1878. Hering first proposed the idea that red, green, blue, and yellow were unique hues (''"Urfarben"''), based on the concept that these colors could not be simultaneously perceived. These hues represented the extremes o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opponent Color Circle 1917
The Opponent may refer to: * The Opponent (1988 film), ''The Opponent'' (1988 film), a 1988 film starring Daniel Greene * The Opponent (2000 film), ''The Opponent'' (2000 film), a 2000 film starring Erika Eleniak See also * * * * * Opposition (other) * Antagonist (other) * Villain (other) {{DEFAULTSORT:Opponent, The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LMS Color Space
LMS (long, medium, short), is a color space which represents the response of the three types of Cone cell, cones of the human eye, named for their responsivity (sensitivity) peaks at long, medium, and short wavelengths. The numerical range is generally not specified, except that the lower end is generally bounded by zero. It is common to use the LMS color space when performing chromatic adaptation (estimating the appearance of a sample under a different illuminant). It is also useful in the study of color blindness, when one or more cone types are defective. Definition The cone response functions \bar(\lambda), \bar(\lambda),\bar(\lambda) are the color matching functions (CMFs) for the LMS color space. The chromaticity coordinates (L, M, S) for a spectral distribution J(\lambda) are defined as: : L = \int^\infty_0 J(\lambda)\bar(\lambda)d\lambda : M = \int^\infty_0 J(\lambda)\bar(\lambda)d\lambda : S = \int^\infty_0 J(\lambda)\bar(\lambda)d\lambda The cone response function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychophysics
Psychophysics is the field of psychology which quantitatively investigates the relationship between physical stimulus (physiology), stimuli and the sensation (psychology), sensations and perceptions they produce. Psychophysics has been described as "the scientific study of the relation between stimulus and Sensation (psychology), sensation" or, more completely, as "the analysis of perceptual processes by studying the effect on a subject's experience or behaviour of systematically varying the properties of a stimulus along one or more physical dimensions". ''Psychophysics'' also refers to a general class of methods that can be applied to study a perceptual system. Modern applications rely heavily on threshold measurement, ideal observer analysis, and Detection theory, signal detection theory. Psychophysics has widespread and important practical applications. For instance, in the realm of digital signal processing, insights from psychophysics have guided the development of models a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Color System
The Natural Colour System (NCS) is a proprietary perceptual color model. It is based on the color opponency hypothesis of color vision, first proposed by German physiologist Ewald Hering. The current version of the NCS was developed by the Swedish Colour Centre Foundation, from 1964 onwards. The research team consisted of Anders Hård, Lars Sivik and Gunnar Tonnquist, who in 1997 received the AIC Judd award for their work. The system is based entirely on the phenomenology of human perception as opposed to color mixing. It is illustrated by a color atlas, marketed by NCS Colour AB in Stockholm. Definition The NCS states that there are six elementary color percepts of human vision—which might coincide with the psychological primaries—as proposed by the hypothesis of color opponency: white, black, red, yellow, green, and blue. The last four are also called unique hues. In the NCS all six are defined as elementary colors, irreducible qualia, each of which would b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complementary Colors
Complementary colors are pairs of colors which, when combined or mixed, cancel each other out (lose chroma) by producing a grayscale color like white or black. When placed next to each other, they create the strongest contrast for those two colors. Complementary colors may also be called "opposite colors". Which pairs of colors are considered complementary depends on the color model that one uses: * Modern color theory uses either the RGB additive color model or the CMY subtractive color model, and in these, the complementary pairs are red–cyan, green–magenta (one of the purples), and blue–yellow. * In the traditional RYB color model, the complementary color pairs are red–green, yellow– purple, and blue– orange. * Opponent process theory suggests that the most contrasting color pairs are red–green and blue–yellow. * The black–white color pair is common to all the above theories. These contradictions stem in part from the fact that traditional color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Wheel
A color wheel or color circle is an abstract illustrative organization of color hues around a circle, which shows the relationships between primary colors, secondary colors, tertiary colors etc. Some sources use the terms ''color wheel'' and ''color circle'' interchangeably; however, one term or the other may be more prevalent in certain fields or certain versions as mentioned above. For instance, some reserve the term ''color wheel'' for mechanical rotating devices, such as color triangle, color tops, filter wheels or the Newton disc. Others classify various color wheels as ''color disc'', ''color chart'', and ''color scale'' varieties. History The color wheel dates back to Isaac Newton's work on color and light. In his book ''Opticks'', Newton presented a color circle to illustrate the relations between these colors. The original color circle of Isaac Newton showed only the spectral hues and was provided to illustrate a rule for the color of mixtures of lights, that these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visible Spectrum
The visible spectrum is the spectral band, band of the electromagnetic spectrum that is visual perception, visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light). The optical spectrum is sometimes considered to be the same as the visible spectrum, but some authors define the term more broadly, to include the ultraviolet and infrared parts of the electromagnetic spectrum as well, known collectively as ''optical radiation''. A typical human eye will respond to wavelengths from about 380 to about 750 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 Terahertz (unit), terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions, these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared). The spectrum does not contain all the colors that the human visual system can distinguish. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichromat
Dichromacy (from Greek ''di'', meaning "two" and ''chromo'', meaning "color") is the state of having two types of functioning photoreceptors, called cone cells, in the eyes. Organisms with dichromacy are called dichromats. Dichromats require only two primary colors to be able to represent their visible gamut. By comparison, trichromats need three primary colors, and tetrachromats need four. Likewise, every color in a dichromat's gamut can be evoked monochromatic light. By comparison, every color in a trichromat's gamut can be evoked with a combination of monochromatic light and white light. Dichromacy in humans is a color vision deficiency in which one of the three cone cells is absent or not functioning and color is thereby reduced to two dimensions. Perception Dichromatic color vision is enabled by two types of cone cells with different spectral sensitivities and the neural framework to compare the excitation of the different cone cells. The resulting color vision is si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuteranomaly
Color blindness, color vision deficiency (CVD) or color deficiency is the decreased ability to see color or differences in color. The severity of color blindness ranges from mostly unnoticeable to full absence of color perception. Color blindness is usually a sex-linked inherited problem or variation in the functionality of one or more of the three classes of cone cells in the retina, which mediate color vision. The most common form is caused by a genetic condition called congenital red–green color blindness (including protan and deutan types), which affects ''up to'' 1 in 12 males (8%) and 1 in 200 females (0.5%). The condition is more prevalent in males, because the opsin genes responsible are located on the X chromosome. Rarer genetic conditions causing color blindness include congenital blue–yellow color blindness (tritan type), blue cone monochromacy, and achromatopsia. Color blindness can also result from physical or chemical damage to the eye, the optic nerve, pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Vision Deficiency
Color blindness, color vision deficiency (CVD) or color deficiency is the decreased ability to color vision, see color or differences in color. The severity of color blindness ranges from mostly unnoticeable to full absence of color perception. Color blindness is usually a Sex linkage, sex-linked Heredity, inherited problem or variation in the functionality of one or more of the three classes of cone cells in the retina, which mediate color vision. The most common form is caused by a genetic condition called congenital red–green color blindness (including protan and deutan types), which affects ''up to'' 1 in 12 males (8%) and 1 in 200 females (0.5%). The condition is more prevalent in males, because the opsin genes responsible are located on the X chromosome. Rarer genetic conditions causing color blindness include congenital blue–yellow color blindness (tritan type), blue cone monochromacy, and achromatopsia. Color blindness can also result from physical or chemical dam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linguistic Relativity
Linguistic relativity asserts that language influences worldview or cognition. One form of linguistic relativity, linguistic determinism, regards peoples' languages as determining and influencing the scope of cultural perceptions of their surrounding world. Various colloquialisms refer to linguistic relativism: the Whorf hypothesis; the Sapir–Whorf hypothesis ( ); the Whorf-Sapir hypothesis; and Whorfianism. The hypothesis is in dispute, with many different variations throughout its history. The ''strong hypothesis'' of linguistic relativity, now referred to as linguistic determinism, is that language ''determines'' thought and that linguistic categories limit and restrict cognitive categories. This was a claim by some earlier linguists pre-World War II; (a debate between university professors) since then it has fallen out of acceptance by contemporary linguists. Nevertheless, research has produced positive empirical evidence supporting a ''weaker'' version of linguistic re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-alternative Forced Choice
Two-alternative forced choice (2AFC) is a method for measuring the sensitivity of a person or animal to some particular sensory input, stimulus, through that observer's pattern of choices and response times to two versions of the sensory input. For example, to determine a person's sensitivity to dim light, the observer would be presented with a series of trials in which a dim light was randomly either in the top or bottom of the display. After each trial, the observer responds "top" or "bottom". The observer is not allowed to say "I do not know", or "I am not sure", or "I did not see anything". In that sense the observer's choice is forced between the two alternatives. Both options can be presented concurrently (as in the above example) or sequentially in two intervals (also known as two-interval forced choice, 2IFC). For example, to determine sensitivity to a dim light in a two-interval forced choice procedure, an observer could be presented with series of trials comprising two su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
