A new approach to motion-estimation for hybrid image sequence coding is presented. Instead of minimizing the displaced frame difference (DFD), the estimator introduced in this paper maximizes the probability to determine the ’true’ physical motion of the scene. The probability expression is derived from two models, one for the statistics of the prediction error image and one for the interdependency of vectors in a vectorfield. The physical vectorfield is smoother than the vectorfield of a DFD-estimator and stronger statistical bindings between vectors exist. Therefore a coding algorithm for the vectorfield combining contour coding of regions of similar displacement with predictive coding of the vectors inside each region proves efficient. This allows the estimator to work with decreased blocksize and (even in DFD sense) to supply a distinctly improved displacement-compensation without spending more datarate for displacement-compensation than the DFD- estimator.