VARID: Viewpoint-Aware Re-IDentification of Vehicle Based on Triplet Loss

With the increasing prevalence of intelligent traffic control and monitoring, research on vehicle re-identification (Re-ID) draws substantial attention in recent years. Different from other cross-view searching tasks such as person Re-ID, the vehicle Re-ID problem is more challenging and unpredictable as viewpoint variations can greatly affect the appearance of vehicles. Existing studies mainly focus on extracting global features based on visual appearance to represent the identity of the target vehicle, while the impact of viewpoint variation is rarely considered. In this paper, we take the view information into account to boost vehicle Re-ID, and introduce latent view labels by clustering and incorporates view information into deep metric learning to tackle the challenge. We also develop a stricter center constraint to further improve the intra-class compactness of feature space. Moreover, we adopt an orthogonal regularization to increase the separability between different vehicles. VARID achieves 79.3% mAP on VeRi-776 and 88.5% mAP on VehicleID which surpasses state-of-the-arts a lot. More comprehensive experimental analyses and evaluations on four benchmarks demonstrate that the proposed method outperforms significantly state-of-the-arts methods.