Gamma

Correction,

Halftones, and

ScreensConfiguring the printer through the control panel is described in chapter 4, “Printer Configuration,” of this manual.

Gamma Correction, Halftones, and Screens

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

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.

»Note: The number of gray levels at 600x600 dpi and 1200x600 dpi is the same. The enhanced print quality is due to elongated halftone cells rather than to an increased number of gray levels.

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 1660 Print Sys- tem creates halftone cells by mapping each gray level onto a collec- tion of dots.

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QMS 1660 Print System Reference