He holds a Ph.D. in Electrical Engineering from West Virginia University (USA). He received a B.S. and a M.S. in Biomedical Engineering from Xi’an Jiaotong University, China. His research interests include biometrics, pattern recognition, computer vision and image processing with focus on cross-spectral recognition of face, periocular regions and partial face. He is a member of IEEE and SPIE. He serves as the reviewer of several academic journals, such as Neurocomputing, Machine Vision and Applications, Optical Engineering.