Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240, China and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA.|Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240, China and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA.|Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240, China and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA.|Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240, China and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240, China and Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA.