QMS 1060, User Manual

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About Gamma
Correction
QMS 1060 Print System Reference 5-6
Screen Angle
A screen angle is the angle at which a halftone screen prints. The
default screen angle for your QMS 1060 Print System is 45°. This is
the normal angle for black and white printers. You can change the
screen angle through the PostScript setscreen operator.
Gamma Correction Concept
Often in scanned images, gray scaling may be too light or dark to
show details clearly. Using gamma correction on a gray-scale image
is similar to using a graphic equalizer on a home stereo; the range of
gray levels is adjusted for the best possible image. This sharpens
overall midrange contrast while blacks (shadows) and whites (high-
lights) keep their original values. Gamma correction sets grayscale
values specified through the PostScript setgray operator to your
printer’s gray-scale values.
Gamma correction is linked to print resolution. The main benefit of
gamma correction is that it improves the copy quality of a scanned
image by improving halftoning at a given resolution..
Menu Administration/Emulations/PostScript/Gamma Correction
Choices No—Disables gamma correction.
Yes—Enables gamma correction.
Default No
Notes Gamma correction is automatically adjusted when you change
your printer’s resolution, if this option is set to Yes.
Gamma correction applies only to PostScript images.
If turning on gamma correction doesn’t yield a suitable gray-
scale image for your needs, set a specific gamma correction
value through your drawing application or through the
PostScript settransfer operator. (See your drawing application
documentation or the
PostScript Language Reference Manual
for more information.)