Black Detection Circuit And Edge/Line Width Detection Circuit - Canon CLC 1120 Service Manual

F. Black Detection Circuit and Edge/Line Width Detection Circuit
The black detection and edge/line width detection circuits perform the following image
processing using RGR signals:
1. Black Detection
Identifies the color of the pixel in question, and generates its color code.
2. Edge Detection
Detects whether the pixel in question is the edge of an input image or not.
3. Line Width Detection
Detects the width of the line forming the edge of an input image.
Volume 4>Chapter 4>IV-G "Black Detection"
Reference:
1. Black detection (ACS) is performed using the black detection signal (ACSROI) generated
during pre-scanning.
2. The black detection signal (ACSROI), edge signal (EDGE), and line width signal (LWTH)
from the black detection circuit and edge/line width detection circuit are used to generate
UCR signals and to detect black characters, determine the level of sharpness processing, and
to identify black originals (ACS).
COPYRIGHT © 1999 CANON INC.
IP-MAIN PCB
R
B Black detection
G
Figure 4-406
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE PROCESSING SYSTEM
ACSROI
LWTH
Line width
detection
EDGE
4-9