Also related to sensitometry or densitometry which can also be per-
formed using visual matching.
pixel
the smallest discrete element in a picture, usually square, in a digital
system. Short for picture element. These elements can also be irregu-
lar shapes and randomly spaced like silver halide grains in a photo-
graphic emulsion. Also called pel.
PostScript
®
a page description language authored by Adobe Systems. It is used
extensively in the desktop publishing industry to translate digitally
stored images, raster and object types, to a raster-oriented printing
device, such as a laser printer or laser typesetter.
progressives
a four color ink proof made on press, where each plate is printed sep-
arately and in various combinations with the other three so that the
four color images can be properly evaluated for dot gain and the over-
all quality of the color separations. Also called “progs”.
prescan
photometry performed by the scanner before a screen preview.
pseudo-color images
when colors are assigned to monochrome shades to give meaning to
areas in the picture. Often used in satellite imagery to define vegeta-
tion and geological information. Can also refer to simple tinting of
monochrome images, like oil-coloring B&W prints.
RAM
Random Access Memory.
raster
a lattice of parallel lines used to represent an image by varying the
brightness of points on each line. The raster is a regular pattern of
thin, horizontal, equally spaced bars.
refractive index
the factor by which a material, such as glass or water, causes light
wave/particles to change velocity. This change in velocity is a change
in direction rather than speed, since the speed of light is constant.
The result is that light waves change direction when they pass
through a boundary from one material, such as air, to another, such
as glass or water. This change can be viewed directly, as when a mag-
nifying lens bends light, or when water magnifies the part of an object
which is submerged. The change in angle can be calculated from this
Page 186
Software Reference for Scanners
Glossary of Computer Imaging Terms
Summary of Contents for Scanners
Page 1: ...Software Reference for Scanners ...
Page 14: ...Page XIV Software Reference for Scanners Table of Contents ...
Page 36: ...Page 22 Software Reference for Scanners Software Installation IBM PC or Compatible Chapter 3 ...
Page 126: ...Page 112 Software Reference for Scanners Cropping and Sizing Images Chapter 11 ...
Page 132: ...Page 118 Software Reference for Scanners Film Type and Orientation Chapter 12 ...
Page 146: ...Page 132 Software Reference for Scanners Focusing with Coolscan Chapter 14 ...
Page 170: ...Page 156 Software Reference for Scanners The Gamma Curve Editor Dialog Chapter 16 ...
Page 194: ...Page 180 Software Reference for Scanners Troubleshooting Windows ...