Region-specific Metric Learning for Person Re-identification

Person re-identification addresses the problem of matching individual images of the same person captured by different non-overlapping camera views. Distance metric learning plays an effective role in addressing the problem. With the features extracted on several regions of person image, most of distance metric learning methods have been developed in which the learnt cross-view transformations are region-generic, i.e all region-features share a homogeneous transformation. The spatial structure of person image is ignored and the distribution difference among different region-features is neglected. Therefore in this paper, we propose a novel region-specific metric learning method in which a series of region-specific sub-models are optimized for learning cross-view region-specific transformations. Additionally, we also present a novel feature pre-processing scheme that is designed to improve the features' discriminative power by removing weakly discriminative features. Experimental results on the publicly available VIPeR, PRID450S and QMUL GRID datasets demonstrate that the proposed method performs favorably against the state-of-the-art methods.