A device includes a first change detection unit which detects a change region distribution based on the texture information; a second change detection unit which detects a change region distribution based on a background differential method; a texture detection unit, a change-detection-unit weighting storage unit, and a change detection result integration unit, wherein while applying a firm texture differential method to the illumination change as much as possible, a detection unit based on a background differential method is applied to a region to which the texture differential method is not favorably applicable.