Cycle Consistency Based Pseudo Label and Fine Alignment for Unsupervised Domain Adaptation

Unsupervised Domain Adaptation (UDA) aims to transfer knowledge from a well-labeled source domain to an unlabeled target domain with a correlative distribution. Numerous existing approaches process this hard nut by directly matching the marginal distribution between two domains, which confront the obstacle of rough alignment and blurred decision boundary. Recent advances in UDA introduce target pseudo-label and subdomain adaptation to reduce misalignment and distribution discrepancy. Whereas, they frequently ignore that the production of target pseudo-label is so dependent on the source-trained classifier, which without reasonable restriction to discriminate generated pseudo-label is whether confident. Meanwhile, many methods in the subdomain alignment metric ignore exploring the potential distribution discrepancy between same-class samples of the intra-domain. To address these two issues simultaneously, this paper proposes a Cycle Consistency based Pseudo Label and Fine Alignment (CCPLFA) approach for UDA. In particular, firstly, a novel cycle-consistency based pseudo label module is designed, which is a simple yet effective way to alleviate the noise of pseudo labels and improve their semantic correctness. Secondly, we develop a Fine-Alignment distribution matching metric. Which can maximize the feature distribution density of intra-class cross-domains and not overlook the distribution structure of the global aspect. Comprehensive experiment results on four benchmarks demonstrate the capability of plug and play and the well generalization performance of our proposed method.