Biography of the authos.
Zhenwen Ren received M.S. in Communication and Information System from the Southwest University of science and Technology (SWUST). He is currently pursuing the Ph.D. degree in control science and engineering at Nanjing University of Science and Technology (NJUST/NUST), Nanjing , China. He is currently with the Department of School of National Defence Science and Technology, SWUST. And he is a member of the Robot Technology Used for Special Environment Key Laboratory of Sichuan Province, Southwest University of science and Technology. Currently, His research interests include image set classification, sparse representation, low-rank representation, deep learning and their applications in machine learning.

Bin WU received the Ph.D. degree in Control Theory and Control Engineering from Beijing University of Science and Technology (USTB), China, in 1999. He is a professor in the Department of Information Engineering at Southwest University of Science and Technology (SWUST). His current interests include pattern recognition, control theory.

Xiaoqian Zhang is currently with the School of Information Engineering, Southwest University of Science and Technology. His research interest covers subspace clustering, sparse representation, low-rank representation and their applications in image processing.

QuanSen Sun received the Ph.D. degree in Pattern Recognition and Intelligence System from Nanjing University of Science and Technology (NUST), China, in 2006. He is a professor in the Department of Computer Science at NUST. He visited the Department of Computer Science and Engineering, The Chinese University of Hong Kong in 2004 and 2005, respectively. His current interests include pattern recognition, image processing, remote sensing information system, medicine image analysis.