Dell 1355 Color Laser User Manual page 370

To suppress the background of the original to enhance text on the scanned
image.
Values:
Off
On*
Margin Top/Bottom
Purpose:
To specify the value of the top and bottom margins.
Values:
2 mm*/0.1 inch*
0-50 mm/0.0-2.0 inch
Margin Left/Right
Purpose:
To specify the value of the left and right margins.
Values:
2 mm*/0.1 inch*
0-50 mm/0.0-2.0 inch
Margin Middle
Purpose:
To specify the value of the middle margin.
Values:
368
Understanding the Printer Menus
Does not suppress the background.
Suppresses the background of the original to enhance text on the
scanned image.
Specify the value in increments of 1 mm/0.1 inch.
Specify the value in increments of 1 mm/0.1 inch.