Contex XD2490 Service Manual page 41

2, and so on
Density
The light stopping ability of a film. Density is inversely pro-
portional to the amount of light reflected or transmitted by an
image.
Device Dependent Color Space
For example RGB. A device dependent color space, e.g., the
same scan file will appear different when viewed on different
computer displays. For example CIE LAB. A device indepen-
dent color space is one in which color values are absolute, e.g.,
defined by CIE standard. CIE LAB is the central color space
in color management systems (CMS) and is used to translate
between different device dependent color spaces such as scan-
ner RGB and display RGB.
Device Profile
A file used as part of a Color Management System (CMS). A
device profile contains information about the characteristics of
a scanner, computer display or printer. The format for device
profiles (Win95, Colorsync. etc.) is standardized by ICC (In-
ternational Color Consortium).
DIP
Digital Image Processor. Hardware embedded function that
does image enhancement in real-time while scanning.
Dither
To use patterns of different colored pixels to create blended
colors; or, to use dots of different sizes to simulate grayscale
images. (see below)
Dithering
A printing or display device may have only a small number
of grayscale or color values for each device pixel. However,
if the viewer is sufficiently distant from the printed page or
display, the value of neighboring pixels can be set so that the
viewer's eye integrates several pixels to achieve an apparent
improvement in the number of levels or colors that can be
reproduced.
Dots Per Inch (dpi)
A measure of dots in a square inch where the individual ele-
ment is a round dot on the printed page.
DPI
Dots Per Inch, equivalent to Pixels Per Inch. An expression of
resolution of a scanned image.
Appendix - C --- Scanner Terms
DSP
Digital Signal Processor, does image enhancement in real-time
while scanning.
Dual 2D-Adaptive Enhancement
Enhancement processing on the foreground and background
separately. Processing is performed on-the-fly. The separate
enhancement processes are simultaneously performed on dif-
ferent drawing aspects.
Dynamic Range
A measurement of scanner quality; the density difference
between highlights and shadows.
Edit
Modify an entry using standard Windows text-editing tech-
niques.
Emulsion
The light sensitive silver, coated on the clear acetate film base,
that forms the photograph when a picture is taken and the film
is developed.
Equalizing
Distributing all color or tone equally along a density range.
File Format (image)
The format in which a scanned picture is saved. Many pro-
grams can insert or import a picture from a file, if it is saved in
a file format that the program supports. Common file formats
include TIFF (Tagged Image File Format), BMP (Windows
bitmap), JPEG (Joint Photograph Expert Group), and FPX
(FlashPix format).
Flip Horizontal
To flip the picture left/right.
Foreground
Foreground when scanning raster data (black and white, or
monochrome data) refers to the pixels that represent data of
interest (background refers to everything else). Typically,
lines and shapes are represented by black pixels (foreground)
and empty space is represented by white pixels (background).
When scanning grayscale data, background means the gray
level of a region of pixels that surrounds some desired fore-
ground data.
Gamma Adjustment
An adjustment that makes the tone distribution lighter or
darker in an image.
C-3