A mathematical curve representing both the contrast and brightness of an image. The steepness of the curve indicates greater contrast calculated as a trigonometric tangent function.

The range of colours that can be captured or represented by a device. When a colour is outside a device's gamut, the device represents that colour as some other colour.

The editing of an image to reduce the colour gamut so that the image can be displayed or output within the limits of a particular device.

The plotting of an image colour gamut into the CIE colour space.

An image-softening effect utilising a bell shaped Gaussian distribution to apply the softening effect. A "Gaussian" curve (a/k/a "bell curve") is a bell-shaped curve showing a distribution of probability associated with different values of a variant.

A type of process colour separation that determines the amount of black ink used to replace Cyan, Magenta, and Yellow in areas where those three inks overlap.

1)  General meaning: conversion of a liquid to a jelly. This term is used specifically to denote the deterioration of an ink, owing to the partial or complete changing of the medium into an insoluble jelly-like condition, which is unworkable, even with the addition of solvent. 2) Alternative to thixotropic.

Term for fine-art digitally produced prints.

1,073,741,824 or 1 billion bytes.

Garbage in, garbage out. A computer industry slang term.

The degree to which a printed surface possesses the property of reflecting light in a mirror-like manner. (Specular reflection).

Transition between two colours or between black and white. Also known as a gradient.

The smallest component of a photographic image. A single particle of silver or dye cloud. Collectively, the size of those particles.

An intaglio printing process that uses engraved cylinders. Ink is retained in the engraved areas for printing. It is ideal in long-run work and prints on most substrates.

One of the three additive primary colours of light (Red, Green and Blue).

The number of steps available to reproduce a colour in an imaging system. Typically, in an 8 bit system there are 256 grey levels per colour.

An image containing a range of grey levels as opposed to only pure black and pure white.

The showing through of an underlying surface due to the inadequate opacity of an ink film which has been applied to it.

Clamping devices that assist in the transport of substrate from a machine.

The process of reproducing a continuous tone image as a series of various sized dots within a fixed grid that can be reproduced with ink. The finer the dot grid the higher the quality of the reproduction.

A square area in a halftone grid that holds an array of printer dots. A halftone cell can represent a discrete number of grey levels equal to the maximum number of printer dots that the halftone cell can hold, plus l. See also halftone dot.

A bright line tracing the edge of an image. This is usually an anomaly of excessive digital processing to sharpen or compress an image.

The ability of an ink film, as distinct from its substrate, to resist indentation or penetration of a hard object.

The movement of a printed image from a holding (or donor) substrate to another surface by applying a certain temperature and pressure.

Toxic chemicals found in some pigments including lead, chromium, cadmium.
Hertz (Hz.) A measure of frequency equal to cycles per second.

A colour-matching system that allows for the combination of six colours in order to create a larger gamut of reproducible colour.

An alternative printing process that extends the capabilities of printing presses. This system uses stochastic screening, 6-colour printing, and other techniques to expand the possible colour gamut well beyond that of traditional 4-colour processes.

Image An image that is mostly white.

The brightest/lightest area within an image.

A graphical display which represents the distribution of tones within an image. The horizontal co-ordinate represents each pixel value possible from black to white. The vertical values indicate the number of pixels in the image that occur at each value level.

Hue, luminance and saturation: a colour model based on these three co-ordinates of colour, where Hue is the dominant colour, Saturation is colour purity, and Luminance is the light/dark characteristic of the colour.

A photographic system that uses laser light to expose film to a pattern developed by the interference pattern of the laser and the reflection. When these films are viewed under specific conditions a 3-D image is visible.

A colour model that utilises Hue, Saturation, and Brightness as the three co-ordinates, where Hue is the dominant colour, Saturation is the purity of colour, and Brightness is a neutral scale of how light or dark a colour is.

A series of formatting commands that describes the components of graphics and text material presented on the World Wide Web in a consistent manner.

The method that is used to retrieve documents on the World Wide Web. This takes place transparent to the user once the URL (Uniform Resource Locator) address is accessed. (For example, DPI is located at http://dpia.org).

A component of colour notation, or the predominant colour.

This is the attribute or dimension by which one colour is distinguishable from another, one which bears a particular colour name but no qualification as to tone or intensity, i.e.. a colour may vary according to the character of the colour itself whether it is a red, a blue or a green, etc.