  Recently, vehicle similarity learning, also called re-identification (ReID),
has attracted significant attention in computer vision. Several algorithms have
been developed and obtained considerable success. However, most existing
methods have unpleasant performance in the hazy scenario due to poor
visibility. Though some strategies are possible to resolve this problem, they
still have room to be improved due to the limited performance in real-world
scenarios and the lack of real-world clear ground truth. Thus, to resolve this
problem, inspired by CycleGAN, we construct a training paradigm called
\textbf{RVSL} which integrates ReID and domain transformation techniques. The
network is trained on semi-supervised fashion and does not require to employ
the ID labels and the corresponding clear ground truths to learn hazy vehicle
ReID mission in the real-world haze scenes. To further constrain the
unsupervised learning process effectively, several losses are developed.
Experimental results on synthetic and real-world datasets indicate that the
proposed method can achieve state-of-the-art performance on hazy vehicle ReID
problems. It is worth mentioning that although the proposed method is trained
without real-world label information, it can achieve competitive performance
compared to existing supervised methods trained on complete label information.
