Domain-Specific Bias Filtering for Single Labeled Domain Generalization

TL;DR

This paper introduces DSBF, a novel framework for single labeled domain generalization that filters domain-specific bias using unlabeled data, significantly improving model generalization across unseen domains.

Contribution

Proposes a new domain-specific bias filtering method (DSBF) for single labeled domain generalization, combining feature debiasing and classifier rectification to enhance model generalization.

Findings

DSBF outperforms existing methods on multiple datasets.

Theoretical analysis supports the bias filtering approach.

Effective in both SLDG and CDG tasks.

Abstract

Conventional Domain Generalization (CDG) utilizes multiple labeled source datasets to train a generalizable model for unseen target domains. However, due to expensive annotation costs, the requirements of labeling all the source data are hard to be met in real-world applications. In this paper, we investigate a Single Labeled Domain Generalization (SLDG) task with only one source domain being labeled, which is more practical and challenging than the CDG task. A major obstacle in the SLDG task is the discriminability-generalization bias: the discriminative information in the labeled source dataset may contain domain-specific bias, constraining the generalization of the trained model. To tackle this challenging task, we propose a novel framework called Domain-Specific Bias Filtering (DSBF), which initializes a discriminative model with the labeled source data and then filters out its domain-specific bias with the unlabeled source data for generalization improvement. We divide the filtering process into (1) feature extractor debiasing via k-means clustering-based semantic feature re-extraction and (2) classifier rectification through attention-guided semantic feature projection. DSBF unifies the exploration of the labeled and the unlabeled source data to enhance the discriminability and generalization of the trained model, resulting in a highly generalizable model. We further provide theoretical analysis to verify the proposed domain-specific bias filtering process. Extensive experiments on multiple datasets show the superior performance of DSBF in tackling both the challenging SLDG task and the CDG task.