Motion transparency constraint equation based on a wavelet function decomposition

Motion transparency phenomena in image sequences are frequent, but classical methods of motion estimation are unable to deal with them. This paper describes a method for estimating optical flow by a generalization of the brightness constancy assumption to additive transparencies. This assumption is based on three successive images of a sequence. Thus, by a development to its second order, we obtain an extension of the flow constraint equation. In order to resolve this nonlinear equation, the Levenberg-Marquardt algorithm is used to estimate a global motion model based on B-spline wavelets. This description of motion allows to work on a multiscale estimation and then provide an accurate optical flow. This method offers some good results on artificial and natural image sequences. A preliminary application of this technique to data hiding issue is also provide.