A mask region extraction unit extracts a region that is to be masked in a panoramic image. A mask processing unit generates the object image where the region to be masked in the panoramic image is masked. A positioning unit adjusts the direction of a spherical image to the shooting direction of the object image. A mapping processing unit maps the mask-processed object image and the spherical image onto a three-dimensional (3D) object space as textures. A 3D image generator generates a 3D panoramic image, when the 3D panoramic image is viewed in a specified line of sight in such a manner so as to regard the shooting location of the panoramic as a viewpoint position.