Progressive Domain-style Translation for Nighttime Tracking

Nighttime tracking is challenging due to the lack of sufficient training data and scene diversity. Unsupervised domain adaptation is a solution by transferring knowledge from day (source domain) to night (target domain). It typically involves adversarial training with a domain discriminator on the source and target data to learn domain-invariant features. However, the imbalanced source/target distribution can cause overfitting of the domain discriminator, hindering the domain adaptability. To address this issue, we propose a Progressive Domain-Style Translation (PDST) for domain adaptive nighttime tracking. PDST decomposes and recombines domain-invariant content encodings and domain-specific style encodings of different domains. Thus the rich source domain content is translated to the target domain, expanding the inter-class diversity of the target domain to alleviate overfitting. Moreover, a momentum update manner is introduced to progressively estimate the domain-style encoding from multiple features, which more accurately reflects the statistical domain attribute than an individual image-style. Finally, we incorporate two regularization terms to constrain the content and domain-style consistency in the translation process, ensuring the generated source-like target features are valid to facilitate the training of domain adaptation. Exhaustive experiments demonstrate the domain adaptability and SOTA performance of the proposed method in nighttime tracking.