An image information processing apparatus is provided to generate, from
previously held image data, a display image according to a viewpoint
designated by a user, and to communicate with a control apparatus which
can communicate with plural image information processing apparatuses
respectively generating display images and has a controller for
controlling viewpoint information shared by the plural image information
processing apparatuses on the basis of viewpoint information sent from
the image information processing apparatus. This apparatus comprises a
transmitter to calculate the viewpoint information based on a user's
instruction and transmit it to the controller, a receiver to receive from
the controller the viewpoint information for generating the display
image, and an image generator to read the image data corresponding to the
viewpoint information from the previously held image data for generating
the display image, and generate and output the display image to a
display.