1. School of Computer Science, Institute of Artificial Intelligence, National Engineering Research Center for Multimedia Software, Hubei Key Laboratory of Multimedia and Network Communication Engineering, Wuhan University, Wuhan, China
2. School of Computer Science, Faculty of Engineering, The University of Sydney, Camperdown, NSW, Australia
3. National Engineering Research Center of Speech and Language Information Processing, iFlytek Company Ltd., Hefei, China
4. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
5. School of Computer Science and Engineering, Nanyang Technological University, Singapore