3D Motion Estimation of Articulated Objects for Object–Based Analysis–Synthesis Coding (OBASC)

An algorithm for motion estimation of articulated 3D objects for object–based analysis–synthesis coding (OBASC) is presented. For motion estimation an articulated object is first decomposed automatically into flexibly connected object– components. Each rigid 3D object–component is assumed to be connected to the object by spherical joints. Then, the 3D motion of the largest object–component is estimated without considering the other components. Finally, the motion analysis is propagated to the rest of the object–components taking into account the spatial constraints enforced by the spherical joints. The developed algorithm has been incorporated in an OBASC which uses articulated 3D model objects. For the standard videophone test sequence Claire (CIF, 10Hz) the transmission rate decreases from 53 kbit/s to 48 kbit/s at a fixed image quality by applying the proposed motion estimation algorithm.