title: Recognizing partially occluded, expression variant faces from single training image per person with SOM and soft kappa-NN ensemble.
abstract: Most classical template-based frontal face recognition techniques assume that multiple images per person are available for training, while in many real-world applications only one training image per person is available and the test images may be partially occluded or may vary in expressions. This paper addresses those problems by extending a previous local probabilistic approach presented by Martinez, using the self-organizing map (SOM) instead of a mixture of Gaussians to learn the subspace that represented each individual. Based on the localization of the training images, two strategies of learning the SOM topological space are proposed, namely to train a single SOM map for all the samples and to train a separate SOM map for each class, respectively. A soft kappa nearest neighbor (soft kappa-NN) ensemble method, which can effectively exploit the outputs of the SOM topological space, is also proposed to identify the unlabeled subjects. Experiments show that the proposed method exhibits high robust performance against the partial occlusions and variant expressions.
authors.affiliation: Department of Computer Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China. x.tan@nuaa.edu.cn
authors.forename: Xiaoyang
authors.initials: X
authors.lastname: Tan
authors.forename: Songcan
authors.initials: S
authors.lastname: Chen
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Zhou
authors.forename: Fuyan
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000465:Algorithms; D001699:Biometry / Q000379:methods*; D016000:Cluster Analysis; D003198:Computer Simulation; D005145:Face / Q000033:anatomy & histology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D016571:Neural Networks, Computer; D009716:Numerical Analysis, Computer-Assisted; D010363:Pattern Recognition, Automated / Q000379:methods*