Joint Transformer and Mamba fusion for multispectral object detection

Multispectral object detection is generally considered better than single-modality-based object detection, due to the complementary properties of multispectral image pairs. However, how to integrate features from images of different modalities for object detection is still an open problem. In this paper, we propose a new multispectral object detection framework based on the Transformer and Mamba architectures, called the joint Transformer and Mamba detection (JTMDet). Specifically, we divide the feature fusion process into two stages, the intra-scale fusion stage and the inter-scale fusion stage, to comprehensively utilize the multi-modal features at different scales. To this end, we designed the so-called cross-modal fusion (CMF) and cross-level fusion (CLF) modules, both of which contain JTMBlock modules. A JTMBlock module interweaves the Transformer and Mamba layers to robustly capture the useful information in multispectral image pairs while maintaining high inference speed. Extensive experiments on three publicly available datasets conclusively show that the proposed JTMDet framework achieves state-of-the-art multispectral object detection performance, and is competitive with current leading methods. Code and pre-trained models are publicly available at https://github.com/LiC2023/JTMDet.