1. Center for Research on Intelligent Perception and Computing (CRIPAC), National Laboratory of Pattern Recognition (NLPR), Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), AI School, University of Chinese Academy of Sciences (UCAS), Beijing, China
2. Microsoft Research, Beijing, China
3. Department of Computer Science, City University of Hong Kong, Hong Kong, China
4. Department of Computer Science, Stony Brook University, Stony Brook, NY, USA