Cue circles: image feature for measuring 3D motion of articulated objects

The shape of articulated objects such as a human body can be simplified into a stick model which is represented by connections of several circular generalized cylinders (GCs). In this paper, we propose a new image feature called cue circles (CCs), and present a method how to obtain CCs from input images. Using CCs, the 3D motion of a human body is measured from a sequence of boundary contour image pairs, which is obtained by an active binocular sensor system. The body model used is represented by a set of cue spheres (CSs), each of which is located at ends of GCs. Stereo matching for recovering the body model is carried out by finding pairs of CCs between the pair of contour images under consideration: a CS is projected on the two image planes as its corresponding CCs