1. An image processing system, comprising: an image selecting device for selecting computer graphics in a figure corresponding to a figure of an actual object and a positional relationship between an observer, who is viewing the actual object, and the actual object; a nimbus generating device for generating a nimbus image around a periphery of the computer graphics; a combined image generating device for generating a combined image combining the computer graphics and the nimbus image; and an image display processing device for displaying the combined image on an display which is viewed by the observer so that the combined image is superimposed on the actual object.