Three-dimensional reference object data indicating a boundary of a reference object contained in a real video image is generated from first data containing the real video image based on a positional relation between a virtual screen position where the real video image is displayed and a virtual camera position corresponding to a camera position. Second data is generated, which indicates an object constituting a virtual three-dimensional CG space generated by reproducing an actual space where the real video image is taken. Third data is data in which the virtual camera position in the virtual three-dimensional CG space is determined in such a manner that the boundary of the reference object in the reference object data and a boundary of the object corresponding to the reference object in the second data are caused to coincide with each other.