Canon DR-2580C Service Manual page 47

5) Binarizing
a) Simple Binarizing
Binary image data can only express
picture elements as either "black" or
"white."
In order to separate the picture ele-
ments into black and white, signals
corresponding to the image brightness
must be cut off at a certain level, so that
anything above that level is judged as
"white" and anything below as "black."
This is called simple binarizing. This is
useful for text documents. Simple bi-
narizing for this machine is called
"Black and White" mode.
The level at which picture elements are
to be divided into white or black is
called the "slice level." The image
brightness is adjusted by changing this
slice level.
White 255
160
128
96
Black 0
Document
Output
Figure 2-511
COPYRIGHT © 2005 CANON ELECTRONICS INC.
1 picture element
White
Slice level
Black
CANON DR-2580C FIRST EDITION APR. 2005
CHAPTER 2 FUNCTION & OPERATION
2-21