SDL: Spectrum-Disentangled Representation Learning for Visible-Infrared Person Re-Identification

Visible-infrared person re-identification (RGB-IR ReID) is extremely important for the surveillance applications under poor illumination conditions. Since the difference in the feature representations not only lies in the person' pose, viewpoint or illumination variations, but also comes from huge spectrum discrepancy, the task becomes practically very challenging. Existing RGB-IR ReID models focus on bridging the gap between RGB and IR images through shared feature embedding, subspace learning or via adversarial learning. However, these methods do not explicitly disregard the spectrum information which is otherwise irrelevant for ReID. Further, adversarial learning methods has less promising convergence. This motivates us to design a non-adversarial and fast disentanglement method to disentangle the spectrum information while learning the identity discriminative features. To extract these features, we propose a novel network with disentanglement loss which can distill identity features and dispel spectrum features. Our network has two branches, spectrum dispelling and spectrum distilling branch. On spectrum dispelling branch, we apply identification loss to learn the identity related and spectrum disentangled features. On spectrum distilling branch, we apply an identity-dispeller loss to fool the identity classifier so that it primarily learns spectrum related information. The entire network is trained in an end-to-end manner, which minimizes spectrum information and maximizes invariant identity relevant information at spectrum dispelling branch. Extensive experiments on existing datasets demonstrate the superior performance of our approach compared to the state-of-the-art.