报告人：林嘉文 (Chia-Wen Lin )副教授，台湾清华大学

时 间：2013年5月20日（周一）下午3:00—4:20

地 点：北京大学计算机研究所大楼 106报告厅（中关村北大街128号）

报告主题: Video Retargeting: Technologies, Applications, and Quality Assessment

Abstract: Video retargeting from a full-resolution video to a lower-resolution display will inevitably cause information loss. Content-aware video retargeting techniques have been studied to avoid critical visual information loss while resizing a video. Maintaining the spatio- temporal coherence of a retargeted video is very critical on visual quality. In the first part of the talk, we will show how to use a panoramic mosaic to guide the scaling of corresponding regions of video frames in a video shot to ensure good spatio-temporal coherence. In the proposed method, a global scaling map for video frames in a video shot is first derived from the panoramic mosaic. Subsequently, the local scaling maps of individual frames are derived from the global map and is further refined according to spatial coherence constraints. Second, we will show how can the proposed video retargeting scheme be used to construct a scalable video coder which supports content-adaptive spatial scalability (e.g., the base-layer and enhancement-layer videos are of different resolution and different aspect ratios) with good coding efficiency. Finally, we will present an objective quality assessment scheme based on geometric distortion and information loss for automatically evaluating the visual quality of a retargeted image.

Bio: Chia-Wen Lin received his Ph.D. degree from the Department of Electrical Engineering, National Tsing Hua University (EE/NTHU), Hsinchu, Taiwan, in January 2000. He has been with EE/NTHU as Associate Professor since August 2007. Prior to joining EE/NTHU, he worked for the Department of Computer Science and Information Engineering, National Chung Cheng University (CSIE/CCU), Chiayi, Taiwan from August 2000 to July 2007. He was with the Information and Communications Research Laboratories, Industrial Technology Research Institute (ICL/ITRI), Hsinchu, Taiwan, during 1992-2000, where his final post was Section Manager. His research interests include video networking and video content analysis. Dr. Lin was awarded the Young Faculty Awards presented by National Chung Cheng University in 2005 and the Ta-You Wu Memorial Awards presented by National Science Council (NSC), Taiwan in 2006. His paper won the Young Investigator Award presented by SPIE VCIP 2005. He serves on the editorial board of IEEE Transactions on Circuits and Systems for Video Technology, IEEE Transactions on Multimedia, IEEE Multimedia Magazine, Journal of Visual Communication and Image Representation, and Signal Processing: Image Communication. He was TPC Co-Chair of IEEE International Conference on Multimedia & Expo (ICME) 2010 and Special Session Co-Chair of IEEE ICME 2009.