Canon MB5450 Series Online Manual page 799

Reducing show-through in text documents or lightening the base color in
recycled paper, newspapers, etc. when scanning documents
Set Reduce Show-through to ON.
OFF
Sharpening slightly out-of-focus images
Set Unsharp Mask to ON.
OFF
Reducing gradations and stripe patterns
Set Descreen to ON.
OFF
ON
ON
ON
799