A Maximum Likelihood Estimator for Choosing the Regularization Parameters in Global Optical Flow Methods

Global optical flow estimation methods based on variational calculus contain a regularization parameter which controls the tradeoff between the different constraints on the optical flow field. The counterpart to the regularization parameter are the hyper-parameters in the Bayesian framework. These hyper-parameters have distinct physical meanings and thus can be inferred from the observable data. We derive a combined marginal maximum likelihood/maximum a posteriori (MML/MAP) estimator for simultaneously estimating hyper-parameters and optical flow for all differential variational approaches directly from the observed signal without any prior knowledge of the optical flow. Experiments demonstrate the performance of this optimization technique and show that the choice of the regularization parameter is an essential key-point in order to obtain precise motion estimation.