A Hough transform for detecting the location and orientation of three-dimensional surfaces via color encoded spots

Video-rate three-dimensional (3-D) acquisition is desirable, in particular for capturing the mouth´s shape when modeling the vocal tract. In a new structured light technique, scenes are illuminated by an array of circular spots which are color encoded to resolve spatial ambiguity. The position and shape of the imaged spots depend on the location and orientation of the illuminated 3-D surface. We present a novel 3-D Hough transform (HT) to detect 3-D surface location and orientation via the imaged spots, with voting constraints applied to maximize potential accuracy. This new technique is demonstrated to successfully extract the 3-D data for a moving face from images acquired at video-rate