Canon CANOSCAN D1230 series Service Manual page 41

CHAPTER 2
5. Binary Processing
Binary processing converts the 8-bit grayscale data into binary data in which 1 bit indicates
white or black.
Slice
level
Document
The ASIC sets parameters (slice level) in the slice level register when the host computer
commands binary processing. The comparator compares the image data with the slice level,
and converts the data into binary data consisting of 1 (black) or 0 (white).
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Binary
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processing
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128
127
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1
0
Image data
(8 bits)
Figure 2-18
8 bit grayscale data
A
Comparator A>B
B
Slice level
register
From ASIC
Figure 2-19
©
2001 CANON INC. CANOSCAN D1230U/D2400U REV.0 MAR. 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
1
1
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1
1
0
0
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0
0
Binary data Output image
(1 bit)
Binary data
(1 bit)