An object based motion method for video coding

In order to improve efficiency of video coding, temporal redundancy between neighboring frames can be reduced. In MPEG-2, some frames, named interframes, are predicted using a motion estimation based on the conservation of the intensity over time. In the new standard MPEG-4, frames are separated into several objects that are transmitted separately. Therefore, the prediction has to be performed on objects instead of frames. So, interframe-objects have to be predicted in order to improve video coding efficiency. The goal of this paper is to propose a new method for object-based prediction using the level sets. First, we propose an efficient object-based motion estimation. The motion of the objects is estimated by assuming the conservation of the level sets function over time, instead of the conservation of the intensity. Secondly, the estimation of the object motion between two frames is used to predict interframe-objects using both forward and backward motion estimations. The method is evaluated on real sequences, illustrating the potential of our approach for an object-based prediction of interframes.