Sprite generation for frame-based video coding

Sprite coding is a very efficient method for the representation and compression of background video object, which has been accepted by MPEG-4 standard. However, how to automatically generate sprite image from raw video sequence is still an open issue, because the motion of foreground video objects not only disturbs the accuracy of motion estimation but also blurs the generated sprite image. This paper presents a novel technique for the generation of background sprite image with improved Global Motion Estimation (GME) and automatic segmentation. Since GME plays an important role in sprite generation, a hybrid scheme jointing the short-term and long-term motion estimation techniques is first developed in this paper. Automatic video segmentation based on available motion information is incorporated into sprite generation, which can mask moving foreground objects and meanwhile protect background sprite from blur. Therefore, the proposed technique is used to construct high quality sprite directly from raw video sequence. Furthermore, with this technique the existing sprite coding can be extended to the field of frame-based coding. 1