Oki S900 - Manual (Page 37)

USING THE S900 AS A SCANNER > 37
UNITS
The Units button indicates the measuring system that is in
use (inch, cm, or Pixel) (See Width and Height).
DESCREEN
Click on the Descreen button to access a drop-down menu
that allows you to specify the type of document you are
scanning in order to eliminate the moiré pattern* commonly
found in printed matter. You can specify Newspaper,
Magazine, or Catalog.
*Moiré pattern—an undesirable pattern resulting from the incorrect
screen angle of the overprinting halftone.