FAST LONG-TERM MOTION ESTIMATION FOR HIGH DEFINITION VIDEO SEQUENCES BASED ON SPATIO-TEMPORAL TUBES AND USING THE NELDER-MEAD SIMPLEX ALGORITHM

International audienceMulti-frame motion estimation is a new method incorporated into the video coding standard H.264/MPEG-4 Advanced Video Coding (AVC) to improve compression performances. De-pending on content, the motion estimation can be short or long-term. For long-term motion estimation, the initial search point in the reference frame is important. In this paper 1 , we propose a new method for a fast long-term motion estima-tion with high definition (HD) sequences. We use an im-plicit uniform motion model. First we describe the multi-resolution motion estimation based on spatio-temporal tubes. These tubes provide a good initial search point for the long-term motion estimation that follows. Then, the search is re-fined using the Nelder-Mead Simplex method. The global ap-proach reduces computational cost and improves the accuracy of motion estimation