TIENet: A Tri-Interaction Enhancement Network for Multimodal Person Reidentification

Multimodal person reidentification (ReID), which aims to learn modality-complementary information by utilizing multimodal images simultaneously for person retrieval, is crucial for achieving all-time and all-weather monitoring. Existing methods try to address this issue through modality fusion to absorb complementary information. However, most of these methods are limited to the spatial domain only and usually overlook the intra-/intermodal interactions during feature fusion, resulting in insufficient learning of modality-specific and complementary information. To address these issues, we propose a tri-interaction enhancement network (TIENet), which contains three modules: spatial-frequency interaction (SFI), intermodal mask interaction (IMMI), and intramodal feature fusion (IMFF). Specifically, the SFI boosts the modality-specific representation by integrating the amplitude-guided attention mechanism into the phase space, combined with spatial-domain convolution to achieve fine-grained information learning. Meanwhile, the IMMI enhances the richness of the feature descriptors by embedding the intermodal relationships to preserve complementary information. Finally, the IMFF module considers the structure of the human body and integrates intramodal contextual information. Extensive experimental results demonstrate the effectiveness of our method, achieving superior performances on RGBNT201 and MARKET1501_RGBNT datasets.