Canon DR-2580C Service Manual page 46

CHAPTER 2 FUNCTION & OPERATION
4) Edge Emphasis
Edge emphasis is a kind of processing
which emphasizes the brightness change
in order to make the image appear sharp.
(Figure 2-509)
White
Output
Edge portion
Black
Before edge emphasis
The processing is performed by compar-
ing the data in the conversion table pro-
vided for performing edge emphasis, with
the target picture element data (a). (Figure
2-510)
The stages in edge emphasis can be
changed by changing the conversion table
and reproduction ratio (B) of the conver-
sion table.
Target picture
element
Conversion table
2-20
1 picture element
Edge portion
Figure 2-509
Target picture
element (a)
0 -a 0
-a -a
4a
0 -a 0
Main-scanning
direction
Figure 2-510
COPYRIGHT © 2005 CANON ELECTRONICS INC.
White
Black
After edge emphasis
For example, if the target picture element
data is increased fourfold and the other
four points multiplied by-1, the overall
brightness will remain unchanged.
B
32
B : 1~64
CANON DR-2580C FIRST EDITION APR. 2005
Output