The purpose of vehicle re-identification(vehicle reID)is to identify the same vehicle through different cameras. However, vehicle reID is a very challenging task due to the large intra-class difference and the large inter-class similarity of vehicle images. This paper proposes a vehicle reID method based on double-branch network feature fusion to solve this problem. The method uses two branches and batch drop block strategies to extract and fuse global features and local features for highlighting the intra-class similarities and inter-class differences. At the same time, the method uses circle loss terms instead of the traditional triplet loss terms and cross-entropy loss terms to construct the objective function. Extensive experiments of the method are conducted on the two public datasets VeRi-776 and VehicleID, and results show that its search accuracy is improved by about 5% compared with the existing methods, which verifies the effectiveness of the method.
表 2 不同方法在VehicleID数据集的实验结果Table 2 Results on the VehicleID dataset using different methods
表 4 VehicleID数据集上圆损失项的性能对比结果Table 4 Results of circle loss term on the VehicleID dataset
表 3 VeRi-776数据集上圆损失项的性能对比结果Table 3 Results of circle loss term on the VeRi-776 dataset
图1 车辆类内差异性与类间相似性示意图Fig.1 Schematic diagram of intra-class differences and inter-class similarity of vehicles
图2 FDNet网络结构Fig.2 FDNet network structure
图3 FDNet在VeRi-776数据集上的可视化结果Fig.3 Visualization images of FDNet method on VeRi-776 dataset
图4 两个数据集上的CMC曲线Fig.4 CMC curves on two datasets
表 1 不同方法在VeRi-776数据集上的实验结果Table 1 Results on the VeRi-776 dataset using different methods