DeH4R: A Decoupled and Hybrid Method for Road Network Graph Extraction
This addresses a critical problem in geospatial computer vision for applications like urban planning and navigation, offering a novel hybrid approach that improves both accuracy and speed.
The paper tackles the challenge of extracting complete and precise road network graphs from remote sensing imagery by proposing DeH4R, a hybrid model that combines graph-generating efficiency with graph-growing dynamics, achieving state-of-the-art performance with a 4.62 APLS and 10.18 IoU improvement over prior methods while being approximately 10 times faster.
The automated extraction of complete and precise road network graphs from remote sensing imagery remains a critical challenge in geospatial computer vision. Segmentation-based approaches, while effective in pixel-level recognition, struggle to maintain topology fidelity after vectorization postprocessing. Graph-growing methods build more topologically faithful graphs but suffer from computationally prohibitive iterative ROI cropping. Graph-generating methods first predict global static candidate road network vertices, and then infer possible edges between vertices. They achieve fast topology-aware inference, but limits the dynamic insertion of vertices. To address these challenges, we propose DeH4R, a novel hybrid model that combines graph-generating efficiency and graph-growing dynamics. This is achieved by decoupling the task into candidate vertex detection, adjacent vertex prediction, initial graph contruction, and graph expansion. This architectural innovation enables dynamic vertex (edge) insertions while retaining fast inference speed and enhancing both topology fidelity and spatial consistency. Comprehensive evaluations on CityScale and SpaceNet benchmarks demonstrate state-of-the-art (SOTA) performance. DeH4R outperforms the prior SOTA graph-growing method RNGDet++ by 4.62 APLS and 10.18 IoU on CityScale, while being approximately 10 $\times$ faster. The code will be made publicly available at https://github.com/7777777FAN/DeH4R.