Oce 3121 Technical & Service Manual page 294

AI Outline processing
AI outline processing emphasises the edges of characters.
When image data input is as shown in figure D, the CPU assumes the presence
of characters and initiates outline processing.
Black
White
When image data input is as shown in figure F, the CPU assumes the presence
of a photo and does not initiate outline processing.
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White
Negative/Positive Reversal
The negative/positive reversal circuit executes the following image processing:
Negative/positive reversal
I
Framing
I
Blanking
I
Pasting
I
518 TSM Océ 3121
Main scanning direction
D
Main scanning direction
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Main scanning direction
White
E
Functional description