A three-dimensional sense adjusting unit displays three-dimensional images to a user. If a displayed reaches a limit of parallax, the user responds to the three-dimensional sense adjusting unit. According to acquired appropriate parallax information, a parallax control unit generates parallax images to realize the appropriate parallax in the subsequent stereo display. The control of parallaxes is realized by optimally setting camera parameters by going back to three-dimensional data. Functions to realize the appropriate parallax are made into and presented by a library.