SimMMDG: A Simple and Effective Framework for Multi-modal Domain
  Generalization
Hao Dong Ismail Nejjar Han Sun Eleni Chatzi Olga Fink
In real-world scenarios, achieving domain generalization (DG) presents
significant challenges as models are required to generalize to unknown target
distributions. Generalizing to unseen multi-modal distributions poses even
greater difficulties due to the distinct properties exhibited by different
modalities. To overcome the challenges of achieving domain generalization in
multi-modal scenarios, we propose SimMMDG, a simple yet effective multi-modal
DG framework. We argue that mapping features from different modalities into the
same embedding space impedes model generalization. To address this, we propose
splitting the features within each modality into modality-specific and
modality-shared components. We employ supervised contrastive learning on the
modality-shared features to ensure they possess joint properties and impose
distance constraints on modality-specific features to promote diversity. In
addition, we introduce a cross-modal translation module to regularize the
learned features, which can also be used for missing-modality generalization.
We demonstrate that our framework is theoretically well-supported and achieves
strong performance in multi-modal DG on the EPIC-Kitchens dataset and the novel
Human-Animal-Cartoon (HAC) dataset introduced in this paper. Our source code
and HAC dataset are available at https://github.com/donghao51/SimMMDG.