Canon DR-2580C Service Manual page 45

c) Custom Adjustment
This is used when data conversion
other than brightness and contrast
adjustments is required.
It is possible for the user to use a
custom conversion table for converting
the gamma curve to the document
image data. In this case, the bright-
ness and contrast adjustments be-
come invalid, and the unique gamma
curve is given priority.
White
(255)
YH
Y0
YL
Black
(0)
Before conversion
Figure 2-508
COPYRIGHT © 2005 CANON ELECTRONICS INC.
(+)
(-)
X0
White
(255)
CANON DR-2580C FIRST EDITION APR. 2005
CHAPTER 2 FUNCTION & OPERATION
2-19