Image sequence coding using multiple-level segmentation and affine motion estimation

A very low bit-rate video codec using multiple-level segmentation and affine motion compensation is presented. The translational motion model is adequate to motion compensate small regions even when complex motion is involved; however, it is no longer capable of delivering satisfactory results when applied to large regions or the whole frame. The proposed codec is based on a variable block size algorithm enhanced with global motion compensation, inner block segmentation, and a set of motion models used adaptively in motion compensation. The experimental results show that the proposed method gives better results in terms of the bit rate under the same PSNR constraint for most of the tested sequences as compared with the fixed block size approach and traditional variable block size codec in which only translational motion compensation is utilized.