🤖 AI Summary
For domain generalization under unknown target domains, this paper proposes the Test-time Inverse Domain Transformation (TIDT) paradigm: leveraging diffusion models to inversely map target-domain images in latent space back to the source-domain distribution, enabling pre-trained downstream models to generalize robustly without fine-tuning. The method requires only source-domain text descriptions—no large-scale synthetic data generation—and is compatible with black-box task models and multi-source diffusion models. Core technical contributions include diffusion latent-space inverse transformation, source-domain semantic-guided reconstruction, and multi-model ensemble for robustness enhancement. Evaluated on BDD100K-Night (segmentation), ImageNet-R (classification), and DarkZurich (detection), TIDT achieves relative performance gains of 137%, 68%, and 62%, respectively, unifying support across three major vision tasks while significantly reducing deployment costs for domain adaptation.
📝 Abstract
Generative foundation models contain broad visual knowledge and can produce diverse image variations, making them particularly promising for advancing domain generalization tasks. While they can be used for training data augmentation, synthesizing comprehensive target-domain variations remains slow, expensive, and incomplete. We propose an alternative: using diffusion models at test time to map target images back to the source distribution where the downstream model was trained. This approach requires only a source domain description, preserves the task model, and eliminates large-scale synthetic data generation. We demonstrate consistent improvements across segmentation, detection, and classification tasks under challenging environmental shifts in real-to-real domain generalization scenarios with unknown target distributions. Our analysis spans multiple generative and downstream models, including an ensemble variant for enhanced robustness. The method achieves substantial relative gains: 137% on BDD100K-Night, 68% on ImageNet-R, and 62% on DarkZurich.