Xerox 8830 User Manual page 18

The Background Suppression area contains a means to correct for
documents that contain poor contrast between the foreground image and the
background. Four choices are provided:
Auto (factory default) The selection uses a prescanned sample of the lead
edge of the document to determine the foreground and the
background of the document. The background is automatically
suppressed. This setting works well for most documents. If the
characteristics of the lead edge are different from the rest of the
document, another setting may work better.
Use this selection for documents with a dark background. The
setting uses a prescanned sample of the lead edge of the document
to determine the foreground and the background of the document.
In this mode, the background is not suppressed, but the foreground
image is improved to increase the contrast.
This selection works best for documents with medium levels of
colored background on opaque media, or for documents on
translucent or transparent media, such as vellum (tracing paper) or
film. The selection uses a prescanned sample of the lead edge of
the document to determine the foreground and the background of
the document.
Off This setting produces a document that reproduces all the
characteristics of the original document with minimum alteration.
Choose this selection when the lead edge of the document is very
different from the rest of the document. If Photo is selected as the
Original Type, the Off setting is automatically selected. Maps with
grayscale or color content may copy best in this mode.
All four settings may be adjusted further by changing the contrast setting
under Copy.
Image Quality
Original
Type
Background
Suppression
Off
Mixed
Photo
Line
Auto
8825/8830 DDS User Guide/10
Reduction &
Enlargement
Copy
Auto
Manual
Preset