Patent ID: 7636113
Filing Date: 2009-12-22
Classification: H04N

Abstract:
1. A noise reduction apparatus for a digital camera which has an imager for imaging a photographic subject, comprising: a dark exposure processor that performs two dark exposure operations including a primary dark exposure operation and a secondary dark exposure operation to obtain corresponding two dark output values for each picture element of the imager, in which the photographic subject is imaged, under a condition where the imager is shaded, after a normal exposure operation in which the photographic subject is imaged; a representative value calculating processor that calculates a representative value for the primary dark exposure operation and the secondary dark exposure operation, based on the two dark output values; a ratio calculating processor that calculates a ratio of each calculated representative value by dividing the representative value for the primary dark exposure operation by the representative value for the secondary dark exposure operation; a noise component calculating processor that calculates noise components caused by a dark current in each said picture element of the imager in said normal exposure operation, on the basis of said ratio; and a noise reducing processor that reduces said noise components from respective output values of each said picture element in said normal exposure operation.