20160302-06 李培华：From Dictionary of Visual Words to Subspaces

【16-06期VALSE Webinar活动】

报告人：李培华 (大连理工大学信息与通信工程学院)

报告时间：2016年3月2日（星期三）北京时间晚20:00

主持人：刘日升

报告题目：From Dictionary of Visual Words to Subspaces: Locality-constrained Affine Subspace Coding

文章信息：Peihua Li, Xiaoxiao Lu, Qilong Wang. From Dictionary of Visual Words to Subspaces: Locality-constrained Affine Subspace Coding. Int. Conf. on Computer Vision and Pattern Recognition (CVPR), 2015,  pp. 2348-2357, 2015.

报告摘要：The locality-constrained linear coding (LLC) is a very successful feature coding method in image classification. It makes known the importance of locality constraint which brings high efficiency and local smoothness of the codes. However, in the LLC method the geometry of feature space is described by an ensemble of representative points (visual words) while discarding the geometric structure immediately surrounding them. Such a dictionary only provides a crude, piecewise constant approximation of the data manifold. To approach this problem, we propose a novel feature coding method called locality-constrained affine subspace coding (LASC). The data manifold in LASC is characterized by an ensemble of subspaces attached to the representative points (or affine subspaces), which can provide a piecewise linear approximation of the manifold. Given an input descriptor, we find its top-k neighboring subspaces, in which the descriptor is linearly decomposed and weighted to form the first-order LASC vector. Inspired by the success of usage of higher-order information in image classification, we propose the second-order LASC vector based on the Fisher information metric for further performance improvement. We compare with state-of-the-art methods and experiments have shown the LASC method is very competitive.

报告人简介：Peihua Li is a professor of School of Information and Communication Engineering, Dalian University of Technology (DUT). Before that, he was a professor, an associate professor of School of Computer Science in Heilongjiang University. He received Ph.D degree in computer science and technology from Harbin Institute of Technology (HIT) in 2003, and then working for one year as a postdoctoral fellow at INRIA/IRISA, Rennes, France. He achieved the best Ph.D dissertation award from HIT in 2004, and honorary nomination of National Excellent Doctoral dissertation in China in 2005. He was supported by Program for New Century Excellent Talents in University of Chinese Ministry of Education. His team achieved the second-best ranking position among all the teams in ALISC 2015: Alibaba Large-scale Image Search Challenge. His research interests include computer vision, pattern recognition and statistical learning. He has published scientific papers in top journals and conferences including ICCV、CVPR and ECCV.

报告材料[Slides]