DBCNet: Dynamic Bilateral Cross-Fusion Network for RGB-T Urban Scene Understanding in Intelligent Vehicles

Understanding urban scenes is a fundamental capability required of intelligent vehicles. Depth cues provide useful geometric information for semantic segmentation, thus complementing RGB (color) data. Although single-modal RGB images are improved by depth information, semantic segmentation may be degraded in poor-visibility conditions. Thermal imaging can address some limitations of depth data. Therefore, we leverage the multimodal information in RGB-and-thermal (RGB-T) images by introducing a dynamic bilateral cross-fusion network (DBCNet) for RGB-T urban scene understanding. First, RGB-T features extracted by a given backbone are regrouped as high- or low-level features. Second, multimodal high-level features are sent to a dynamic bilateral cross-fusion module for further refinement. Third, a bounded high-level semantic-feature integration module is added to provide feature guidance, and a multitask supervision mechanism is used for fine-tuning. Extensive experiments on two RGB-T urban scene-understanding datasets indicate that DBCNet aggregates multilevel deep features effectively and outperforms state-of-the-art deep-learning scene-understanding methods.