Complementary Masked-Guided Meta-Learning for Domain Adaptive Nighttime Segmentation

Semantic segmentation in nighttime scenes presents a significant challenge in autonomous driving. Unsupervised domain adaptation (UDA) offers an effective solution by learning domain-invariant features to transfer models from the source domain (daytime scenes) to the target domain (nighttime scenes). Many methods introduce a latent domain to reduce the difficulty of UDA. However, they often build only a single adaptation pair of "latent-to-target", which limits the effectiveness of knowledge transfer across different domains. In this letter, we propose a Masked Guided Meta-Learning (MGML) framework for domain-adaptive nighttime semantic segmentation. Within the MGML framework, we explore two key issues: how to generate the latent domain, and how to leverage the latent domain to assist meta-learning in reducing domain discrepancy. For the first issue, we employ the fast Fourier transform along with a complementary masking strategy to generate masked latent images that resemble the target scenes in the latent domain without adding to the training burden. For the second issue, we nest a mask-based consistency constraint within a bi-level meta-learning framework, enabling cross-domain knowledge acquired from the pair of "source-to-latent" to enhance the "latent-to-target" adaptation. Experiments on benchmark datasets demonstrate that our MGML achieves state-of-the-art performance, demonstrating the effectiveness of our approach in nighttime semantic segmentation.