Abstract: A document to be scanned is corner referenced on a transparent platen, with the document's image facing down. The platen defines an X-Y coordinate system. A moving line of light extends in the X direction and illuminates the document's image, line by line, as the line of light moves in the Y direction. The line of light that is thus reflected from the document is sensed by a linear CCD sensor array having a large number of individual sensor cells arranged in a line that extends in the X direction and coincides with the line of light. Multiple reference marks embodied in one or more reflection targets are located at a known position relative to the platen and/or its document referencing corner, to be scanned prior to scanning the document.