Canon 4205B002 User Manual page 652

Reducing show-through in text documents or lightening the base color in recycled paper,
newspapers, etc. when scanning from the ADF (Auto Document Feeder)
Set Reduce Show-through to Low or High according to the degree of show-through or darkness of the
base color.
None Low
Sharpening slightly out-of-focus images
Set Unsharp Mask to ON.
OFF
Reducing gradations and stripe patterns
Set Descreen to ON.
OFF
Note
"Moire" is a phenomenon where uneven gradation or a stripe pattern appears when such photos or
pictures printed with fine dots are scanned. Descreen is the function for reducing this moire effect.
Reducing dust and scratches
Set Reduce Dust and Scratches to Low, Medium or High according to the degree of dust and scratches.
None
ON
ON
Medium