DisplayMaker Legacy ColorMark+ - User Guide

B-5
density range of an image, but rather the distribution of its den-
sity. The brightening (with gamma > 1) or darkening (with
gamma < 1) occurs mainly in the midtones.
With gamma > 1, highlights are compressed and shadows are
expanded; with gamma < 1, highlights are expanded and shad-
ows are compressed. Gamma correction is often used to
smoothly expand details in the shadows. This is often required
with transparent originals. Monitors also require gamma correc-
tion.
gamma curve
A particular type of tone curve. When the value of a gamma
curve is 1, the curve is at a 45-degree angle and straight, leaving
the input and output densities the same. A gamma higher than 1
brightens the output; a gamma lower than 1 darkens the output.
The further the gamma is from 1, the more the curve bulges.
Gamma curves are used for gamma correction.
gamut
The range of colors that can be reproduced by a device, such as a
printer, monitor, or offset press.
gray balance
In process printing, indicates the proportions of cyan, magenta,
and yellow to obtain a neutral gray, that is, a gray with no appar-
ent color cast.
gray component replacement (GCR)
A color separation technique that substitutes black ink for calcu-
lated amounts of cyan, magenta, and yellow ink. GCR econo-
mizes on inks because one ink (black) does the job of three
(cyan, magenta, and yellow). It also economizes on time because
only one ink has to dry. Good printing requires economical use
of all ink to avoid exceeding the capacity of the paper to absorb
it. Using black ink brings out better detail and contrast in an
image.
gray levels
Discrete tonal steps in a continuous tone image, inherent to digi-
tal data. Most contone images will contain 256 gray levels per
color.