Fast and robust sprite generation for mpeg-4 video coding

Abstract. This paper presents a fast and robust sprite generation algorithm for MPEG-4 video coding. Our contributions consist of two aspects. Firstly, a fast and robust Global Motion Estimation (GME) algorithm is proposed here. Spatial and temporal feature point selection schemes are incorporated into the hierarchical GME in order to speed up it. Experimental results demonstrate our method is up to seven times faster than the traditional one in MPEG-4 video verification model, and meanwhile the accuracy is slightly improved. Secondly, a sprite generation scheme with some novel techniques is developed. Rough image segmentation is also introduced for the purpose of image blending in sprite generation. The proposed algorithm can significantly improve the visual quality of the generated sprite image and the reconstructed background object in video coding. Furthermore, the proposed GME and sprite generation algorithms can be used for both frame-based and object-based video coding. Keywords. video coding, global motion estimation, sprite generation, MPEG-4