Hierarchical motion estimation with content-based meshes

Two-dimensional mesh-based models provide a good alternative to motion estimation and compensation. The estimation of the best node-point motion vectors is a challenging task. To this effect, Nakaya and Harashima (1994) proposed a hexagonal matching procedure. Toklu et al. improved the hexagonal search algorithm in terms of both motion-estimation accuracy and computational complexity by employing a hierarchy of regular meshes. Recognizing the limitations of regular meshes, Van Beek et al. (1997) extended Toklu et al.'s (1996) work by utilizing content-based meshes. Here, we provide an alternative hierarchical motion-estimation method with content-based meshes where hierarchical representations are employed for both the images and the irregular meshes in order to provide further improvements in computational complexity as well as motion accuracy. The comparison results are provided with real video sequences.