School of Computer Science and Technology, Anhui University, Hefei 230039, Anhui, China and Key lab of Image Processing & Analysis of Anhui Province, Hefei 230039, Anhui, China;School of Computer Science and Technology, Anhui University, Hefei 230039, Anhui, China;Department of Information Engineering and Computer Science, Feng Chia University, Taiwan;School of Computer Science and Technology, Anhui University, Hefei 230039, Anhui, China