Canon CANOSCAN D1230 series Service Manual page 40

2) Averaging
When reading images at lower resolution, the thinned data increases resulting in output
image deterioration. Averaging is a process in which the data to be thinned and the data to be
actually output are averaged and output, in order to suppress the image deterioration due to
the data thinning.
CCD
reading
data
Output
image
data
CCD
reading
data
Output
image
data
Averaged data=(A+B+C+D)/4
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COPYRIGHT 2001 CANON INC. CANOSCAN D1230U/D2400U REV.0 MAR. 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
A B C
A
B C
Thinned data
A B C
A'
Figure 2-17
D E F G
D E F G
D E F G
E'
CHAPTER 2
H
H
H
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