Ricoh Gestetner 5428C, Service Manual

Page: 105 / 152

31 October 2001 IMAGE PROCESSING
6-15
Detailed
Descriptions
6.4.6 BINARY PROCESSING
This process converts the video signal from 8-bit to 1-bit (black and white) in
accordance with a threshold value.
The threshold value depends on a compensation curve (gamma curve) which
corresponds to selected image processing settings. For example, if a darker image
is selected, a compensation curve that converts each pixel value to a higher
number is selected. This ensures accurate generation of the 256 gray scales from
black to white.
6.4.7 FINE MODE
Purpose: Use this function to make clear prints.
This machine’s specification is 300 dpi.
With this function, the scanner scans at 400 dpi in the sub-scan direction by
reducing the scanner motor speed, then the master making unit writes at 400 dpi in
the master feed direction by reducing the master feed motor speed. Therefore, the
resolution in the paper feed direction is 400 dpi.
Normal Fine mode
Main-scan
direction
Sub-scan
direction
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