A value for expressing distance from a virtual viewpoint is set to every
predetermined compositional unit of a first image; a second image is
generated; a coefficient is defined corresponding to the value for
expressing the distance set to every predetermined compositional unit;
and the first image and the second image are synthesized based on the
coefficient defined for every predetermined compositional unit. This
successfully creates an image with a natural perspective by which the
compositional unit is blurred according to the distance thereof from the
virtual viewpoint, while causing only a small load to CPU.