A horizontal evaluation data generation section calculates an average value of pixel signals in a vertical optical black region based on given pixel data in the horizontal optical black region and outputs the calculated average value to an evaluation section. A vertical evaluation data generation section calculates an average value of pixel signals in a vertical optical black region based on given pixel data in the vertical optical black region and outputs the calculated average value to the evaluation section. The evaluation section outputs a gain value according to the difference between the two sent average values to a computing section. A smear information memory stores pixel signals in a line in the vertical optical black region. The computing section multiplies the pixel data stored in the smear information memory by the sent gain value, and subtracts the multiplied pixel data from the pixel data imaged by the CCD 5.