Extending the 'Oriented Smoothness Constraint' into the Temporal Domain and the Estimation of Derivatives of Optical Flow

Recent experimental results by Schnorr 89 with an approach based on a simplified ‘oriented smoothness constraint’ show considerable improvement at expected discontinuities of the optical flow field. It thus appears justified to study whether the local gray value variation can be exploited in the temporal as well as in the spatial domain in order to achieve further improvements at discontinuities in the optical flow field associated with the image areas of moving objects in image sequences. An extension of the oriented smoothness constraint into the temporal domain is presented. In this context, a local estimation approach for the spatio-temporal partial derivatives of optical flow has been developed. This, in turn, is used to compare two approaches for the definition of optical flow.