Joint Intensity and Spatial Metric Learning for Robust Gait Recognition

Yasushi Makihara, Atsuyuki Suzuki, Daigo Muramatsu, Xiang Li, Yasushi Yagi; Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2017, pp. 5705-5715

This paper describes a joint intensity metric learning method to improve the robustness of gait recognition with silhouette-based descriptors such as gait energy images. Because existing methods often use the difference of image intensities between a matching pair (e.g., the absolute difference of gait energies for the l_1-norm) to measure a dissimilarity, large intrasubject differences derived from covariate conditions (e.g., large gait energies caused by carried objects vs. small gait energies caused by the background), may wash out subtle intersubject differences (e.g., the difference of middle-level gait energies derived from motion differences). We therefore introduce a metric on joint intensity to mitigate the large intrasubject differences as well as leverage the subtle intersubject differences. More specifically, we formulate the joint intensity and spatial metric learning in a unified framework and alternately optimize it by linear or ranking support vector machines. Experiments using the OU-ISIR treadmill data set B with the largest clothing variation and large population data set with bag, b version containing carrying status in the wild demonstrate the effectiveness of the proposed method.