Image Processing - Canon DR-9080C Service Manual

V. IMAGE
PROCESSING
1. Image Processing Within the Unit
Fig. 2-501 shows a block diagram of the
image processor.
Image reading
unit
300/600 dpi
DMA controller
Personal computer
The image processing within the machine is
performed in IC154 (QQ-Chip) within the main
CPU PCB.
With the reading unit, the optical resolution
can be switched between 600 dpi and 300 dpi
from the personal computer. For example, when
the resolution set in the personal computer is 300
dpi or less (300, 240, 200, 150, 100), the optical
resolution of the unit is set to 300
COPYRIGHT © 2003 CANON ELECTRONICS INC.
IC154 within the main CPU PCB (QQ-Chip)
Image
acquisition unit
10bit 8bit
RGB rearranging
JPEG module
JPEG
Fig. 2-501
CANON DR-6080/9080C REV.0 SEPT. 2003
CHAPTER 2 FUNCTIONS & OPERATION
Image
processor 1
Image resolution
conversion
Image
processor 3
Edge enhancement
Simple binary
Error diffusion
Automatic brightness adjustment
dpi. And, when 400 dpi or 600 dpi is set on the
computer side, 600 dpi is set on the reading unit
side. The image data scanned by the unit are
processed (A/D
correction) within the unit, and then are output as
10-bit digital signals to the main CPU PCB.
Image data
SDRAM
SDRAM_I/F
Document orientation
(image rotation)
Image
processor 2
Brightness adjustment
Contrast adjustment
Gamma correction
conversion and shading
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