An output value calculating unit 5 performs weighting arithmetic operations on a plurality of filter values calculated by a filter value calculating unit 4 by using a feature quantity detected by a feature quantity detecting unit 1, a directional correlation value calculated by a directional correlation value calculating unit 2 and an amplitude level calculated by an amplitude level calculating unit 3, and multiplies a result of the weighting arithmetic operations by a sensitization magnification to create pixel signals of a correctly exposed image.