contrast

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contrast

1. (in painting) the effect of the juxtaposition of different colours, tones, etc.
2. 
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

Contrast

A juxtaposition of dissimilar elements to show the differences of form or color, or to set in opposition in order to emphasize the differences.

Contrast

 

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.

REFERENCES

Vudvorts, R. Eksperimental’naia psikhologiia. Moscow, 1950.
Teplov, B. M. “Vzaimodeistvie odnovremennykh svetovykh oschchushchenii.” In Zritel’nye oshchushcheniia i vospriiatiia. Moscow-Leningrad, 1935.

contrast

[′kän‚trast]
(communications)
The degree of difference in tone between the lightest and darkest areas in a television or facsimile picture.
(computer science)
In optical character recognition, the difference in color, reflectance, or shading between two areas of a surface, for example,a character and its background.

contrast

The white level of a display screen. The contrast adjusts how bright the white is. See brightness and contrast ratio.
References in periodicals archive ?
The CE-Iohexol programme is designed to develop a Captisol-enabled, next-generation contrast agent for diagnostic imaging with a reduced risk of renal toxicity.
an impaired elimination of the drug), gadolinium-based contrast agents (GBCAs) may increase the risk for nephrogenic systemic fibrosis (NSF), a rare and serious syndrome involving fibrosis of skin, joints, eyes and internal organs.
The most important criteria for optimization diagnostic efficacy and patient safety are relaxivity and stability of contrast agents. (38)
Dr Roditi said gadoliniumbased contrast agents are the only commercial injectable contrast agents used for MRI scans, though others are being researched.
Synthesis of Contrast Agents. Scheme 1 shows the structure and the synthesis of the PEG contrast agents of different structures.
Adverse effects of angiographic contrast agents diminished dramatically by clinical precautions, premedications before the angiography, reducing the amount of contrast agent usage, and also increasing the usage of iso-osmolar nonionic angiographic contrast agents during angiography procedures.
Normal morphology was observed in all the organs examined with H&E staining which indicates that the contrast agents did not grossly alter tissue structure (author PJ).
The Mann-Whitney-Wilcoxon test was used to compare semiquantitative shunt grading using two contrast agents. Statistical significance was assumed when the P value < 0.05.
The only way to do that is with an effective contrast agent.
A disadvantage is that sugar-based contrast agents cannot be used in examinations of diabetes patients.
The global contrast media/ contrast agents market has witnessed high competitive intensity in recent years, with Bayer Healthcare (Germany) and GE Healthcare (U.K.) being the leading market players.
In recent years, research on the use of ferrite nanoparticles in [T.sub.2] contrast agents has shown a great potential application in MR imaging.