Video retargeting has received considerable attention in image processing research recently. Due to the limited memory and extensive computation, it is difficult to re-target a large-size video. Frame-by-frame retargeting cannot solve this problem because of low quality of spatial-temporal coherence. In this paper, we present a new seam-carving-based video retargeting algorithm. First, video frames are read one by one and energy map per frame are calculated based on the gradient. Then energy map