Mobile devices are increasingly powerful in multimedia transmitting and browsing. However, the small screen and different aspect ratios of mobile devices lower visual quality while watching images or videos. Video ret...Mobile devices are increasingly powerful in multimedia transmitting and browsing. However, the small screen and different aspect ratios of mobile devices lower visual quality while watching images or videos. Video retargeting is aim at fitting an existing video into arbitrary size and aspect ratio. Previous content-aware retargeting methods are mostly high computational cost, which limits their applications on the portable devices with low computation ability. In this paper, a new crop-and-scale approach is presented to adapt video to better suit the target display. We automatically find the optimal parameters of cropping window using the dynamic programming method,, and then scale it to fit the target display. The cropping window can smoothly shift during a shot to follow the movement＇of important objects. The retargeting results using our approach introduce no deformation and jitter effects over the whole video. Experimental results show the success of our approach on adapting a variety of source videos to small display sizes.展开更多
We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we mode...We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we model distortion energies to prevent important video contents from deforming. Then, to maintain depth mapping stability, we model disparity variation energies to constraint the disparity range both in spatial and temporal domains. The last component of our method is a non-uniform, pixel-wise warp to the target resolution based on these energy models. Using this method, we can process the original stereoscopic video to generate new, high-perceptual-quality versions at different display resolutions. For evaluation, we conduct a user study; we also discuss the performance of our method.展开更多
The numerous works on media retargeting call for a thorough and comprehensive survey for reviewing and categorizing existing works and providing insights that can help future design of retargeting approaches and its a...The numerous works on media retargeting call for a thorough and comprehensive survey for reviewing and categorizing existing works and providing insights that can help future design of retargeting approaches and its applica- tions. First, we present the basic problem of media retarget- ing and detail state-of-the-art retargeting methods devised to solve it. Second, we review recent works on objective quality assessment of media retargeting, where we find that although these works are designed to make the objective assessment result in accordance with the subjective evaluation, they are only suitable for certain situations. Considering the subjective nature of aesthetics, designing objective assessment metric for media retargeting could be a promising area for investiga- tion. Third, we elaborate on other applications extended from retargeting techniques. We show how to apply the retarget- ing techniques in other fields to solve their challenging prob- lems, and reveal that retargeting technique is not just a simple scaling algorithm, but a thought or concept, which has great flexibility and is quite useful. We believe this review can help researchers and practitioners to solve the existing problems of media retargeting and bring new ideas in their works.展开更多
基金supported by the the Science and Technology Commission of Shanghai Municipality(Grant No.11ZR1413000)the Innovation Program for Graduate Students of Shanghai University(Grant No.SHUCX112125)the Key Laboratory for Advanced Displays and System Appliction(Shanghai University),Ministry of Education,China(Grant No.P201004)
文摘Mobile devices are increasingly powerful in multimedia transmitting and browsing. However, the small screen and different aspect ratios of mobile devices lower visual quality while watching images or videos. Video retargeting is aim at fitting an existing video into arbitrary size and aspect ratio. Previous content-aware retargeting methods are mostly high computational cost, which limits their applications on the portable devices with low computation ability. In this paper, a new crop-and-scale approach is presented to adapt video to better suit the target display. We automatically find the optimal parameters of cropping window using the dynamic programming method,, and then scale it to fit the target display. The cropping window can smoothly shift during a shot to follow the movement＇of important objects. The retargeting results using our approach introduce no deformation and jitter effects over the whole video. Experimental results show the success of our approach on adapting a variety of source videos to small display sizes.
基金supported by the National Basic Research Program of China under Grant No. 2011CB302206the National Natural Science Foundation of China under Grant Nos. 61272226 and 61272231Beijing Key Laboratory of Networked Multimedia
文摘We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we model distortion energies to prevent important video contents from deforming. Then, to maintain depth mapping stability, we model disparity variation energies to constraint the disparity range both in spatial and temporal domains. The last component of our method is a non-uniform, pixel-wise warp to the target resolution based on these energy models. Using this method, we can process the original stereoscopic video to generate new, high-perceptual-quality versions at different display resolutions. For evaluation, we conduct a user study; we also discuss the performance of our method.
文摘The numerous works on media retargeting call for a thorough and comprehensive survey for reviewing and categorizing existing works and providing insights that can help future design of retargeting approaches and its applica- tions. First, we present the basic problem of media retarget- ing and detail state-of-the-art retargeting methods devised to solve it. Second, we review recent works on objective quality assessment of media retargeting, where we find that although these works are designed to make the objective assessment result in accordance with the subjective evaluation, they are only suitable for certain situations. Considering the subjective nature of aesthetics, designing objective assessment metric for media retargeting could be a promising area for investiga- tion. Third, we elaborate on other applications extended from retargeting techniques. We show how to apply the retarget- ing techniques in other fields to solve their challenging prob- lems, and reveal that retargeting technique is not just a simple scaling algorithm, but a thought or concept, which has great flexibility and is quite useful. We believe this review can help researchers and practitioners to solve the existing problems of media retargeting and bring new ideas in their works.
