Patent ID: 7805021

Claim:
In a document handler and imaging system, wherein different document sheets are sequentially moved past an imaging station by a document feeding system to be illuminated by a document illumination source and imaged by a document imager in the document imaging station, wherein the document imaging station includes a document backing surface having a selected color and a scanning sensor having at least two color sensitive channels and wherein at least one edge of a document sheet is detected in said document imaging station by said document imager, comprising: a registration parameter detection circuit configured to: receive image data comprising a representative sample of the backing surface, the image data including chrominance values in multiple channels for selected pixel locations along a scanline; automatically determine an average, chrominance value for each of the multiple channels; select a registration channel from the multiple channels based on the average chrominance values; determine a chrominance deviation for the registration channel; and determine a scanned image alignment registration parameter for aligning a scanned image to the backing surface based on the average chrominance value and the chrominance deviation of the registration channel.