FDMamba: Frequency-Driven Dual-Branch Mamba Network for Road Extraction From Remote Sensing Images

Road extraction from remote sensing imagery is crucial for a variety of applications, including transportation monitoring, disaster response, and urban planning. However, existing methods often fail to accurately delineate sparse, curvilinear, and boundary-blurred road structures in high-resolution images, leading to incomplete detail preservation and inadequate contextual understanding. To address these challenges, we propose a novel Frequency-Driven Dual-Branch Mamba Network (FDMamba) for precise road extraction from remote sensing imagery. The proposed FDMamba integrates frequency-aware modeling with a dual-branch architecture, enabling collaborative learning of fine-grained edge details and global spatial dependencies. Specifically, FDMamba comprises three key modules: a Fourier Reconstruction Attention Mechanism (FRAM) to enhance high-frequency boundary information and low-frequency structural representation; a Rotation-aware Mamba Module (RAMamba) that leverages multi-path state space modeling for robust directional perception of road structures; and a Phase-guided Feature Fusion Module (PFFM) for effective cross-scale alignment and fusion of high- and low-frequency features. Furthermore, to mitigate the issue of blurred or ambiguous boundaries, we introduce a hybrid loss function that combines binary cross-entropy, focal loss, and frequency-aware loss, explicitly guiding the model to focus on edge structure and multi-frequency complementary information. Extensive experiments on three benchmark datasets, CHN6-CUG, DeepGlobe, and Massachusetts, demonstrate that FDMamba consistently outperforms state-of-the-art methods in terms of F1-score and IoU, achieving superior boundary clarity and structural continuity while preserving overall geometric integrity. The code is available at https://github.com/darkseid-arch/RE-FDMamba.