An image combined high sensitivity image and low sensitivity image is provided with well-adjusted white balance and broad dynamic range. The image is obtained by multiplying the combined data by total gain that depends on scene. A white balance is adjusted with gain value calculated from of high output image data. Lv value representing luminance is calculated and compared with a threshold to decide whether or not the high sensitivity image and the low sensitivity image should be combined. First gamma correction unit performs gamma-correction for the image signal derived from the high sensitivity signal with first gamma character, second gamma correction unit performs gamma-correction for the image signal derived from the low sensitivity signal with second gamma character that is different from the first gamma character, and addition unit combines the image signal from the first gamma correction unit and the image signal from the second gamma correction unit.