BROAD CONTEXT BACKGROUND DETECTOR
Original Publication Date: 1983-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
Referring to the drawings, an electronic page scanning system is shown with the document page 3 at object area or platen 4 imaged through a lens 5 onto either a raster imager or an area imager 6. At startup of the system, calibration for gain and offset is carried out by placing a known calibration target in the object area 4.