| Halftone |
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. |
| Halftone
Cell |
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. |
| Halo |
A
bright line tracing the edge of an image. This is usually an anomaly
of excessive digital processing to sharpen or compress an image. |
| Hardness |
The
ability of an ink film, as distinct from its substrate, to resist
indentation or penetration of a hard object. |
| Heat
Transfer |
The
movement of a printed image from a holding (or donor) substrate
to another surface by applying a certain temperature and pressure. |
| Heavy
Metals |
Toxic
chemicals found in some pigments including lead, chromium, cadmium.
Hertz (Hz.) A measure of frequency equal to cycles per second. |
| Hexachrome® |
A
colour-matching system that allows for the combination of six colours
in order to create a larger gamut of reproducible colour. |
| Hi-Fi
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. |
| High
Key |
Image
An image that is mostly white. |
| Highlight |
The
brightest/lightest area within an image. |
| Histogram |
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. |
| HLS |
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. |
| Holography |
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. |
| HSB
(Hue, Saturation, and Brightness) |
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. |
| HTML
(Hypertext Mark-up Language) |
A
series of formatting commands that describes the components of graphics
and text material presented on the World Wide Web in a consistent
manner. |
| HTTP
(Hypertext Transfer Protocol) |
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). |
| Hue |
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. |
