“…RGB–IR-based Person Re-ID is the most widely studied cross-modal setting over all the other alternatives, thanks to the introduction of the SYSU-MM01 dataset [ 45 ], which initiates the path of an RGB–IR-based cross-modal Re-ID scenario. Following the survey paper in [ 13 ], state-of-the-art Re-ID approaches using RGB–IR-based cross-modal methods can be divided into two categories: non-generative- [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ] and generative-based approaches. The former one relies on traditional feature representation [ 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ] and metric learning approaches to maximize the similarities between two images with the same identity and minimize the similarities between two images with different identities, while the latter one depends on the unification of images from different modalities to minimize the data distribution gap between two different modalities.…”