Enforcing Constraints for Human Body Tracking

A novel approach for tracking 3D articulated human bodies in stereo images is presented. We present a projection-based method for enforcing articulated constraints. We define the articulated motion space as the space in which the motions of the limbs of a body belong. We show that around the origin, the articulated motion space can be approximated by a linear space estimated directly from the previous body pose. Articulated constraints are enforced by projecting unconstrained motions onto the linearized articulated motion space in an optimal way. Our paper also addresses the problem of accounting for other constraints on body pose and dynamics (e.g. joint angle bounds, maximum speed). We present here an approach to guarantee these constraints while tracking people.