Scanner Terms - Contex SD One+ Technical Service Manual

Service Guide SD One+
Appendix C

Scanner Terms

Activation Code:
AdaptiveThresholding:
AdaptiveThresholding:
Additive Colors:
ADL+ Error Diffusion Halftoning:
ALE - Accuracy Lens Enhancement:
Is the when the product specific License code has been pared with a Scanner serial no.
Advanced 2-D Adaptive Thresholding estimates the background grey 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 thresholded as a black or a white pixel.
Advanced 2-D Adaptive Thresholding estimates the background grey 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 thresholded as a black or a white pixel.
The additive primary colors are red, green and blue. These additive primaries represent the three main components
of white light. Used individually 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 produce white. Additive color is used in scanners and
computer displays.
Image Processing that supports visibility of greytones in printed output by adding toned shades of grey in regions
between black and white. Carried out as a segment of Dual 2D-Adaptive enhancement processing in copy modes.
Accuracy Lens Enhancement (ALE) is an electronic 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 different 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 demanding 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 electronically correct the spherical errors in the scanner and maintain a stable maximum
error across any two points of less than 0.05% ± 1 pixel.
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