contrast (redirected from Contrast agents)
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1. (in painting) the effect of the juxtaposition of different colours, tones, etc.
a. (of a photographic emulsion) the degree of density measured against exposure used
b. the extent to which adjacent areas of an optical image, esp on a television screen or in a photographic negative or print, differ in brightness
3. Psychol the phenomenon that when two different but related stimuli are presented close together in space and/or time they are perceived as being more different than they really are
A juxtaposition of dissimilar elements to show the differences of form or color, or to set in opposition in order to emphasize the differences.
in psychology, the subjective exaggeration of the differences between perceived objects or between certain sectors of the visual field during their spatial (simultaneous contrast) or temporal (successive contrast) contiguity. Thus, when the color black is placed next to white it seems even blacker. Contrast may also be manifested in color change. For example, a gray square on a red background seems greenish blue; on a blue background it looks orange. The sharpest contrast of two colors is expressed at the boundary of the two areas (boundary contrast). The phenomenon of assimilation is the opposite of contrast. Contrast is widely used in various forms of art and literature.
REFERENCESVudvorts, R. Eksperimental’naia psikhologiia. Moscow, 1950.
Teplov, B. M. “Vzaimodeistvie odnovremennykh svetovykh oschchushchenii.” In Zritel’nye oshchushcheniia i vospriiatiia. Moscow-Leningrad, 1935.
The degree of difference in tone between the lightest and darkest areas in a television or facsimile picture.
In optical character recognition, the difference in color, reflectance, or shading between two areas of a surface, for example,a character and its background.
contrastThe white level of a display screen. The contrast adjusts how bright the white is. See brightness and contrast ratio.