Domain-Specific Conditional Jigsaw Adaptation for Enhancing transferability and Discriminability

Unsupervised Domain Adaptation (UDA) aims to transfer knowledge from a label-rich source domain to a target domain where the label is unavailable. Existing approaches tend to reduce the distribution discrepancy between the source and target domains or assign the pseudo target labels to implement a self-training strategy. However, the transferability or discriminability lackage of the traditional methods results in the limited ability to generalize on the target domain. To remedy this issue, a novel unsupervised domain adaptation framework called Domain-specific Conditional Jigsaw Adaptation Network (DCJAN) is proposed for UDA, which simultaneously encourages the network to extract transferable and discriminative features. To improve the discriminability, a conditional jigsaw module is presented to reconstruct class-aware features of the original images by reconstructing that of corresponding shuffled images. Moreover, in order to enhance the transferability, a domain-specific jigsaw adaptation is proposed to deal with the domain gaps, which utilizes the prior knowledge of jigsaw puzzles to reduce mismatching. It trains conditional jigsaw modules for each domain and updates the shared feature extractor to make the domain-specific conditional jigsaw modules could perform well not only on the corresponding domain but also on the other domain. A consistent conditioning strategy is proposed to ensure the safe training of conditional jigsaw. Experiments conducted on the widely-used Office-31, Office-Home, VisDA-2017, and DomainNet datasets demonstrate the effectiveness of the proposed approach, which outperforms the state-of-the-art methods.