Even in a situation in which an image of the back side of an object cannot be captured, the shape of the object can be generated with high accuracy. For individual images captured from the circumference of an object, projection regions projected in an area from the surface of projection in a projective space to a projective plane that is distant from the surface of projection by a predetermined length in a depth direction in a case where the object reflected in the individual images is projected to the projective space from viewpoint positions of the individual images are detected. A portion common to the individual detected projection regions is extracted.