Contex SD 3600 series, Technical Service Manual

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C-2
Appendix - C --- Scanner Terms
Activation Code
Is the when the product specific License code has
been pared with a Scanner serial no.
AdaptiveThresholding
Advanced 2-D Adaptive Thresholding estimates
the background gray level in a window area around
each pixel. The difference between the actual pixel
value and the background is then compared to the
adaptive settings to determine if a pixel is thresh-
olded as a black or a white pixel
Additive Colors:
The additive primary colors are red, green and
blue. These additive primaries represent the three
main components of white light. Used individu-
ally or together, these three colors of light can be
mixed to create nearly all colors. When these three
primary colors are mixed in equal parts they pro-
duce white. Additive color is used in scanners and
computer displays.
ADL+ Error Diffusion Halftoning
Image Processing that supports visibility of gray-
tones in printed output by adding toned shades of
gray in regions between black and white. Carried
out as a segment of Dual 2D-Adaptive enhance-
ment processing in copy modes.
ALE - Accuracy Lens Enhancement
Accuracy Lens Enhancement (ALE) is an elec-
tronic correction of spherical errors in CCD based
camera- scanning systems.When looking at pixels
across the range of a camera, the pixels tend to
be more elliptical at the outside edges of the lens
and more round in the middle of the lens. This
anomaly is known as a spherical lens error and
can introduce inaccuracies in the scanning system
that can vary quite substantially between differ-
ent points along the scan line. Most manufactures
typically state a +-0.1% accuracy of the scanner
between the two outermost end-points of the scan
line. However, when measuring between two points
that do not fall across the entire scan line, it is not
unusual to see variations of up to +- 0.5% or even
higher. This is naturally unacceptable in demand-
ing environments and markets such as GIS, which
need a stable and well-defined maximum error of
0.1% or less.
ALE solves this problem by a process to electroni-
cally correct the spherical errors in the scanner and
maintain a stable maximum error across any two
points of less than 0.05% ± 1 pixel.
ATAC
Automatic Thickness Adjustment Control - A special
technology that allows the scanner pressure platen
to be raised to accommodate thick originals and
then lowered - both actions performed by pressing
a key from the operators panel. Sensors in the plat-
en detect when perfect pressure is applied to the
the original and automatically stop the downwards
motion of the platen so it rests on the original with
an optimal grip.
Bitmap:
An image format made from a matrix of individual
pixels. .bmp.
Bitmapped Image:
A bitmapped image is a computer file representing
a line-art image that was scanned with a scanner.
Refers to the pattern (map) of bits that are either
black or white.
Black Level
The Black Level is a setting in scan programs
used to change dark graytone colors to true black.
For example, if one is copying a brochure with a
mixture of text and pictures, the text will often be
digitized to a color that we may see as black but
really is a dark graytone. When the printer digests
this graytone data, it will print the original’s text with
a halftone pattern, meaning scattered dots instead
of solid black. By increasing the Black Level value,
one can get the text to be copied in real black and
it will therefore appear clearer.
Black Point Adjustment
An adjustment made that will determine the amount
of shadow detail in an image. It is considered
proper to set the black point so that the darkest
part of an image will only just have zero detail.
Blueprint
A process of photographic printing used mainly for
copying architectural and mechanical drawings;
produces blue lines on a white/bluish background.
Blur
The averaging of pixel elements.
Brightness Adjustment
An adjustment on a scanner that allows the user to
compensate for a light or dark original.
Calibration
Adjusting a device so that it performs in accor-
dance with an established standard. Scanner
calibration is minimizing color deviation between
scanned ANSI IT8 reference color patches and the
known color reference values. Generally, Calibra-
tion is the process of setting a device to known
color conditions - stabilizing the device to a known
and quantifiable state. Calibration is commonly
done with devices that change color frequently,
such as monitors (phosphors lose brightness over
time), scanners (light changes) and printers (proof-
ers and other digital printing devices can change
output when colorant or paper stock is changed).
CALS
Computer-aided Acquisition and Logistics Support
(CALS) standard, a U.S. Defense Department and
industry initiative that addresses the design, manu-
facture, and support issues of generation, access,
management, and use of technical data in digital
form.