Multiple integration model for single-source domain generalizable person re-identification

Abstract

Domain generalizable (DG) person re-identification (re-ID) aims to train a model on labeled source domains which can perform well on invisible target domains. Because of the distribution shifts between different domains, it is a challenging task. Existing methods address this challenge by using multiple source domains to train a model which requires more data, manual labor, and computation. In contrast, we pay attention to the single-source DG re-ID task, that is, only one source domain data is accessible for training. However, due to the limited availability of training data, this task is more difficult. In this paper, a novel MulTiple Integration (MTI) model is introduced for single-source DG person re-ID. By integrating multiple reliable perturbations, the generalization performance can be improved. Specifically, MTI model contains two types of integration modules, one is shallow-level compensation (SLC) and the other is deep-level integration (DLI). For SLC, according to the idea of continual learning, the shallow-level information of the ImageNet pre-trained ResNet-50 branch is introduced and fused with the shallow-level information of our backbone network. In this way, massive information in ImageNet can be used to prevent the disastrous forgetting of the pre-trained information, and information compensation can be provided for backbone network. Additionally, we propose a hybrid integrated normalization layer to fuse information and improve the model’s generalization performance. For DLI, a wave transformer block is introduced in the deep layer of the backbone, which can integrate the information of a batch images and contain reliable disturbance, so that the robustness of the model can be promoted. Extensive experimental results demonstrate the superiority of our model.