Ricoh AP 306D [74/77] Glossary

Printing Guideline for Ricoh Color Products 2.01

14 Glossary

Absolute colorimetric

This rendering intent allows the exact reproduction of colors. Colors which cannot be

reproduced within the output device‘s gamut are reproduced as closely as possible.

This intent is mostly used for simulation of paper white, and for company logos where

a speciÞ c color must be reproduced as accurately as possible.

Calibration

Calibration is the process of adjusting a color device to a known color status. For

output devices such as printers or copiers, this known status is deÞ ned by target

density curves (gamma curves) for the four basic colors cyan, magenta, yellow

and black. Calibration compares the actual status to the target status and applies a

correction to set the device back to the target condition. The method of calibration is

different among various devices.

CMM

See Color Matching Method.

CMS

See Color Management System.

CMYK

Cyan, magenta, yellow, and black, the colors used by output devices such as

printers. Cyan, magenta, and yellow represent the primary colors of the subtractive

color model, which is based on the absoption of light. When light reaches transparent

ink or toner on paper, a certain amount of light is absorbed and the reß ected part is

preserved as color. 0% of cyan, magenta and yellow on paper produces white (paper

white). And, in theory, mixing 100% of the primary colors on paper produces black (all

light is absobed), however, in practice it doesn‘t due to impurities of inks or toners.

Therefore black is added in printing process.

Color Management System (CMS)

A software that allows applications to convert colors from one color space to another.

Examples; Apple ColorSync, Microsoft ICM 2.0.

Color Matching Method (CMM)

This is the engine of a color management system that does the color conversion

calculations from one color space to another using ICC proÞ les. Operating systems

and applications sometimes have built-in or default CMMs, but allow the user to

select other CMMs. Examples; Heidelberg CMM, Apple CMM.

Color Model

A color model is a color measurement scale or system to describe colors in a

numerical way. Examples; RGB, CMYK.

Color Space

A color space is a three-dimensional geometric representation of the colors that can