1. Guangdong Laboratory of Machine Perception and Intelligent Computing, Shenzhen MSU-BIT University, Shenzhen, China
2. School of Information Management, Jiangxi University of Finance and Economics, Nanchang, China
3. Guangdong OPPO Mobile Telecommunications Corp., Ltd., Dongguan, China
4. School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
5. School of Digital Media and Art Design, Hangzhou Dianzi University, Hangzhou, China
6. Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong