A characteristic point extraction unit extracts a characteristic point in an overlapping region of a plurality of component images picked up using a camera built in portable equipment and having pan angles or elevation angles different from each other. A self-position estimation unit estimates three-dimensional coordinate values of the characteristic point and three-dimensional coordinate values of a camera position, which are associated with each other, at the same time in two component images in which the camera positions are displaced from each other. A panoramic image generation unit adjusts, based on the estimated three-dimensional coordinate values of the camera position, the three-dimensional coordinate values of the characteristic point of the component image to correct the component image and combine a plurality of component images having pan angles or elevation angles different from each other to generate a synthesis image.