In a first case a trimmed image generating section carries out trimming such that respective lateral direction lengths of a rear processed image and rear lateral processed images in the combined image are equal, and in a second case in which the trimmed image generating section judges that there is information that is included in the images of the first overlapping regions and is not included in the images of the second overlapping regions and information that should be included in the combined image, the trimmed image generating section carries out trimming such that the information that should be included in the combined image remains in the rear lateral processed images, and, as compared with the first case, the lateral direction length of the rear processed image in the combined image is short, and the lateral direction lengths of the rear lateral processed images in the combined image are long.