QMS 860, User Manual, Page: 188 / 398

About Gamma Correction
Gamma Correction is the compression or expansion of the ranges
of dark or light shades in a printed image to provide the best copy
of scanned images.
Terms
Several terms related to gamma correction are explained in this
section to help you better understand the gamma correction
concept.
Gray Levels are a progressive series of gray tones between black
and white. Gray levels are obtained by varying the ratio of black to
white dots. The number of gray levels depends on printer resolution
and screen frequency.
Halftone is a printed copy of a scanned image as a set of tiny,
evenly spaced spots of variable diameter that, when printed,
visually blur together to appear as shades of gray. Your QMS 860
Print System creates halftone cells by mapping each gray level onto
a collection of dots.
Factors that influence the quality of a halftone are
■ Device resolution of the printer
■ Screen frequency of the halftone
■ Quality of the scan
■ Diameter of the laser beam
Chapter 6
P r i n t Q u a l i t y 6 - 3