Projectors display a movie of a tourist resort, which is a background image, on screens, and video cameras take video by overlapping a subject walking on a treadmill with the background image. Therefore, the subject can be naturally combined in the background image, and also can enjoy a virtual experience...http://www.google.fr/patents/US7164441?utm_source=gb-gplus-shareBrevet US7164441 - Video image producing method and apparatus
