1. Department of Computer Science, Norwegian University of Science and Technology, Gjøvik, Norway
2. Engineering Research Center of Learning-Based Intelligent System (Ministry of Education), the Key Laboratory of Computer Vision and System (Ministry of Education), and the School of Computer Science and Engineering, Tianjin University of Technology, Tianjin, China
3. Jiangsu Province Key Lab on Image Processing and Image Communication, Nanjing University of Posts and Telecommunications, Nanjing, China