gamma

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gamma

1. the third letter in the Greek alphabet (Γ, γ), a consonant, transliterated as g. When double, it is transcribed and pronounced as ng
2. the third highest grade or mark, as in an examination
3. a unit of magnetic field strength equal to 10--5 oersted. 1 gamma is equivalent to 0.795 775 × 10--3 ampere per metre
4. Photog Television the numerical value of the slope of the characteristic curve of a photographic emulsion or television camera; a measure of the contrast reproduced in a photographic or television image
5. 
a. involving or relating to photons of very high energy
b. relating to one of two or more allotropes or crystal structures of a solid
c. relating to one of two or more isomeric forms of a chemical compound, esp one in which a group is attached to the carbon atom next but one to the atom to which the principal group is attached

gamma

(gam -ă) (γ) The third letter of the Greek alphabet, used in stellar nomenclature usually to designate the third-brightest star in a constellation or sometimes to indicate a star's position in a group.

Gamma

 

(1) A conventional unit that is sometimes used for measurements of small masses: 1 gamma = 10-6 g. The designation “microgram” (μg) is more frequently used than “gamma.”

(2) The name of a hundred-thousandth part of an oersted (the unit of magnetic field strength in the cgs system of units) that is used mainly for measurements of terrestrial magnetism and cosmic magnetic fields. It is designated by y.


Gamma

 

the quantitative characteristic of the ability of photographic material to transmit the difference in exposure H of various parts of a photographic image by the difference in the optical density D of the parts. The gamma is equal to the tangent of the angle of inclination to the axis log H of the straight portion of the performance curve of the material (provided that the scales of the axes log H and D are identical). Other conditions being equal, the gamma characterizes the uniformity of the silver halide crystals of the photographic emulsion with respect to light sensitivity. As a rule, it is greater for low-sensitivity positive materials and less for high-sensitivity negative materials. The gamma is one of the most important sensitometric parameters of a photographic material.

gamma

[′gam·ə]
(chemistry)
The gamma position (the third carbon atom in an aliphatic carbon chain) on a chemical compound.
(electromagnetism)
A unit of magnetic field strength, equal to 10 microoersteds, or 0.00001 oersted.
(graphic arts)
A numerical indication of the degree of contrast in a television or photographic image; equal to the slope of the straight-line portion of the H and D curve for the emulsion or screen.
(mechanics)
A unit of mass equal to 10-6 gram or 10-9 kilogram.

GAMMA

(language)
1. A language for matrices and generation of mathematical programming reports.

["GAMMA 3.3 for MPS/MPSX, IBM System:/360", Bonnor & Moore Assocs (Mar 1975)].

2. A high-level parallel language.

[Research Directions in High-Level Parallel Languages, LeMetayer ed, Springer 1992].

gamma

Gamma is a number that represents the relationship between digital pixels and luminance, which is inherently nonlinear. For years, there has been a misconception that gamma had to be corrected due to the inherent deficiency in earlier CRT monitors. In fact, the CRT generated almost the inverse of a human's perception of luminance and thus actually evened out this relationship.

Gamma Correction
A gamma correction number is applied to ensure that the digital pixels produce a uniform luminance across the entire tonal realm from dark to bright, especially in the midtones. Because LCD monitors were designed to emulate the CRT's gamma, gamma correction is still used. With gamma correction, eight bits per pixel is sufficient; otherwise, 11 bits per pixel would be required. See color depth and pixel.