Glossary, Brightness, Cluster-dot screening – Oki 8c Plus User Manual

Page 19: Mapping, Colour management system, Colour models, English glossary

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Colour Guide

19

English

Glossary

Brightness

Along with hue, and saturation, brightness is one of the three dimensions
of colour. It is the property that describes the intensity of light reflected
or transmitted by an object or source, independent of hue or saturation.

Cluster-dot screening

This is a halftoning method that uses multiple pixels that vary from small
to larger dots as the colour gets darker. It is characterized by a polka-dot
look.

Colour gamut

The range of colours that a device can produce is known as its colour
gamut. Devices are unable to produce all colours that occur in nature so
their colour gamut is a subset of this.

Colour Management System (CMS)

A system used to communicate colour fidelity across devices such as
input, display and output to ensure that the best colour rendition possible
is given at all times.

Colour mapping

This is the translation of colour representation from one device (or system)
to another.

Colour models

A colour model is a system that allows colours to be arranged or identified.
There are various models in existence, with some more suitable to specific
applications than others.

RGB

Computer monitors for example, use red, green and blue phosphors to
display images and colours are specified using the RGB model.

CMY(K)

Cyan, magenta, yellow and black are the inks used in the four colour
print process and there is a model used to describe this. Due to the
imperfections in printing inks, black is added rather than produced by
mixing the other three inks. Black is identified as ‘K’ to avoid confusion
with other colours such as blue.

HSL

Colours are defined by hue, saturation and lightness.

HSB

Colours are defined by hue, saturation and brightness. The dimensions
are similar to the HSL model but the HSB model is related to the RGB
system.

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