Using a single imaging device like a video camera for tracking the

Official title: {using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected (tracking a projected light spot to determine a position on a display surface G06F3/0386)}

G06F3/0425 (Using a single imaging device like a video camera for tracking the) appears on 2,136 US grants and 2,770 published applications in this corpus.