Canon imageRUNNER C3220 Copying Manual page 318

3
Press [Remove Background].
If the background color remains, or if you want to make the background color
darker when the original is scanned in the Remove Background mode, make fine
adjustments to the density of the background color.
If you want to make fine adjustments to the density of the background color,
press [Fine Adjustment] © press [-] or [+] to specify the amount of each color
that you want to remove © press [OK].
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For example, if the background color (yellow) of the original remains, press [-]
next to <Yellow> to adjust the density.
Adjusting Yellow automatically adjusts the levels of Red and Green to the same
level as Yellow. However, adjusting the levels of Red or Green sets Yellow back to
its default level.
7-22 Image Quality Adjustment