An efficient coding scheme based on image alignment for H.264/AVC

The translational motion model of H.264/AVC limits its coding efficiency for video sequences that have more complicated motions. Although an affine motion model was proposed before for overcoming the above limitation, existing methods seem to be complicated to implement. In this paper, we investigate a simple coding scheme based on image alignment to improve the quality for video sequences undergoing a special kind of distortion. With a single global affine transformation applied to a video sequence of this kind, the transformed image frame is geometrically more similar to the target frame. When such an alignment image frame is used as the reference frame, residual error is reduced and hence video quality is improved. Experimental results on both a synthetic video sequence and a real world sequence have shown that the proposed scheme outperforms H.264/AVC reference software and is simpler than existing methods employing affine transformation.