A viewpoint position-related parameter setting unit determines which approximate spherical shape to use in order to determine a viewpoint position. A viewpoint position creation unit creates a plurality of approximate spherical shapes set by the viewpoint-position-related parameter setting unit, and creates respective viewpoint positions. An optimal viewpoint position creation unit calculates a rotation angle at which the number of slave viewpoints associated with master viewpoints is substantially equal and a maximum distance between the master viewpoint and the slave viewpoint associated therewith is a minimum.