His research interests include pattern recognition, image processing, neural networks, machine learning, and especially the applications to character recognition and document analysis. He has contributed many effective methods to different aspects of handwritten document analysis, including image pre-processing, page segmentation, feature extraction, classifier design, and character string recognition. His algorithms have yielded superior performance, and have been transferred to industrial applications including mail sorting, form processing and Web document retrieval. He has published over 200 technical papers at prestigious international journals and conferences, including IEEE T-PAMI, IJCV, Pattern Recognition, IEEE T-NNLS, IEEE T-IP, ICPR, ICDAR, CVPR, ICDM, AAAI and IJCAI. He won the IAPR/ICDAR Young Investigator Award of 2005, and received the Outstanding Youth Fund of NSFC in 2008. He is an associate Editor-in-Chief of Pattern Recognition Journal, and associate editor of Image and Vision Computing, International Journal on Document Analysis and Recognition, and Cognitive Computation. He is a Fellow of the IAPR and the IEEE.