XEROX WIDE FORMAT COPY SYSTEM Document quality • 35
Determining document quality Some documents require additional adjustments to obtain the best copy
quality. Documents of good quality are easy to scan and usually give
good copies on the first attempt. Documents of bad quality may require
more than one attempt, using different settings, to obtain the best copy
quality.
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A good quality document has all of these characteristics:
• The contrast between the foreground (the image of interest) and
the background is high. The foreground may be color or black.
• The foreground is a solid, high-density black or dark color (or
dark blue on a blueline, or dark brown on a sepia). The
foreground density is uniform. There is only one kind of
foreground (e.g., there are no pencil additions on a blueline). If
the document is of mixed type, the foreground is color.
• If the document is white on black or white on blue, the
foreground is clear white or nearly white, and the background is
a solid, high-density black or dark color.
• The background is white or light-colored and is free of speckling
or other noise. The background density is uniform.
• The document has no creases, folds, stains, tears or extraneous
marks that the Scan System might interpret as foreground.
Bad quality documents often require special attention to achieve a
usable image. Fortunately, image processing technology is incorporated
that can extract acceptable images from documents degraded by many
kinds of problems.
A bad quality document has one or more of the following problems:
• The foreground is light (e.g., a faded or overexposed blueprint or
light pencil lines).
• The foreground has variable density (i.e., some parts are dark
and some parts are light).
• The foreground consists of two or more densities or colors (e.g.,
pencil additions on an ink drawing, or pencil or ink additions on a
sepia).
• The background is medium dark or dark (e.g., underexposed
blueprint).
• The background has variable density.
• The background has speckles.