From a plurality of imaging units (110) which capture images of a vehicle periphery and from an image taken by any one of the plurality of imaging units (any one of 111, 121, 131, 141), a value corresponding to brightness of the image is calculated. Based on the calculated value, brightness of images obtained by the plurality of imaging units (110) is corrected by a brightness correction unit (120). After a predetermined coordinate transformation is performed on the brightness corrected images, the images are combined into a single image, and the single image is displayed together with the image taken by the one imaging unit (any one of 111, 121, 131, 141).