Uncertainty-Guided Mixup for Semi-Supervised Domain Adaptation without Source Data
This addresses domain adaptation for scenarios where source data is unavailable due to privacy or bandwidth constraints, representing an incremental improvement in semi-supervised methods.
The paper tackles semi-supervised domain adaptation without access to source data, proposing uncertainty-guided Mixup to reduce intra-domain discrepancy and align domains, achieving superior performance over recent baselines on various datasets.
Present domain adaptation methods usually perform explicit representation alignment by simultaneously accessing the source data and target data. However, the source data are not always available due to the privacy preserving consideration or bandwidth limitation. Source-free domain adaptation aims to solve the above problem by performing domain adaptation without accessing the source data. The adaptation paradigm is receiving more and more attention in recent years, and multiple works have been proposed for unsupervised source-free domain adaptation. However, without utilizing any supervised signal and source data at the adaptation stage, the optimization of the target model is unstable and fragile. To alleviate the problem, we focus on semi-supervised domain adaptation under source-free setting. More specifically, we propose uncertainty-guided Mixup to reduce the representation's intra-domain discrepancy and perform inter-domain alignment without directly accessing the source data. Finally, we conduct extensive semi-supervised domain adaptation experiments on various datasets. Our method outperforms the recent semi-supervised baselines and the unsupervised variant also achieves competitive performance. The experiment codes will be released in the future.