Appeal No. 1998-2679
Application No. 08/148,765
improve the shadow-to-highlight characteristics of both
neutral and colored images during reproduction. The shadow-
to-highlight characteristic of color images typically
corresponds to the changes in the perceived image when the
image includes objects containing both brightly lit
(highlight) areas and shadow areas. Each of the devices, a
cathode ray tube (CRT) or a scanner, includes what is called a
color space or color metric. Typically, for scanners it is
scanner RGB (Red, Green, Blue), for CRT's it is CRT RGB and
for printers it is printer CMY (Cyan, Magenta, Yellow). RGB
and CMY represent the "color primaries" that define the color
space or color metric. These color spaces are therefore
defined by the color primaries of the devices. The different
spaces have different characteristics. For example, a
particular color, say purple, in the RBG type spaces is
created by adding together the three primaries RGB in
different amounts, such that RGB spaces are called "additive"
spaces. In contrast, the same color in a CMY space is created
by using the primary dyes of the printer to further or
subject-out light incident on the print and is called a
subtractive. To print an image that is input by a scanner
requires that the original RGB image be transformed into a
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