QMS 1060, User Manual

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About Gamma
Correction
5-3 Additional Technical Information
About Gamma Correction
Terms
Several terms related to gamma correction are explained in this sec-
tion to help you better understand the gamma correction concept.
Gray Levels
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
A 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 1060 Print Sys-
tem creates halftone cells by mapping each gray level onto a collec-
tion of dots.
Factors that influence the quality of a halftone are
n
Printer resolution
n
Screen frequency of the halftone
n
Quality of the scan
n
Quality of the original image
n
Diameter of the laser beam
Changing print resolution from 300x300 dpi to 600x600dpi smooths
the resulting spots. In addition, because each spot is represented by
a wider range of dots, more gray levels are possible. The laser beam
is part of the print engine, so it’s not a factor you can adjust.