Achieving high accuracy on data from domains unseen during training is a
fundamental challenge in domain generalization (DG). While state-of-the-art DG
classifiers have demonstrated impressive performance across various tasks, they
have shown a bias towards domain-dependent information, such as image styles,
rather than domain-invariant information, such as image content. This bias
renders them unreliable for deployment in risk-sensitive scenarios such as
autonomous driving where a misclassification could lead to catastrophic
consequences. To enable risk-averse predictions from a DG classifier, we
propose a novel inference procedure, Test-Time Neural Style Smoothing (TT-NSS),
that uses a "style-smoothed" version of the DG classifier for prediction at
test time. Specifically, the style-smoothed classifier classifies a test image
as the most probable class predicted by the DG classifier on random
re-stylizations of the test image. TT-NSS uses a neural style transfer module
to stylize a test image on the fly, requires only black-box access to the DG
classifier, and crucially, abstains when predictions of the DG classifier on
the stylized test images lack consensus. Additionally, we propose a neural
style smoothing (NSS) based training procedure that can be seamlessly
integrated with existing DG methods. This procedure enhances prediction
consistency, improving the performance of TT-NSS on non-abstained samples. Our
empirical results demonstrate the effectiveness of TT-NSS and NSS at producing
and improving risk-averse predictions on unseen domains from DG classifiers
trained with SOTA training methods on various benchmark datasets and their
variations.

本论文提出了一种基于测试时间神经风格平滑和神经风格平滑训练程序的领域泛化风险规避分类器，该分类器使用神经风格转移模块实现实时的图片风格调整，并在测试时利用黑盒访问领域泛化分类器，通过对多种风格的图像的识别结果进行综合以提高预测抗风险的能力，并在已有领域泛化方法中具有可无缝集成性。