Canon GP405 Service Manual page 103

2. Binary Processing (photo mode)
In photo mode, image data is subjected to screen processing, enabling 256 gradations while
still using binary image data. The flow of processing is as shown in Figure 4-311.
As many as 4 x 8 pixels are treated as a single unit, and pixels are distributed into 256 patterns
according to the mode of density distribution. The units of 4 x 8 pixels are divided so that the pixels
in question are arranged at 45°, forming a screen pattern.
4 pixels
8 pixels
To a darker pattern
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
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Figure 4-311
CHAPTER 4 IMAGE FORMATION SYSTEM
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