Building-Road Collaborative Extraction From Remote Sensing Images via Cross-Task and Cross-Scale Interaction

Buildings and roads are the two most basic man-made environments that carry and interconnect human society. Building and road information has important application value in the frontier fields of regional coordinated development, disaster prevention, and auto-driving. Mapping buildings and roads from very high-resolution (VHR) remote sensing images has become a hot research topic. However, the existing methods often extract buildings and roads with separate models, ignoring their strong spatial correlation. To fully utilize their complementary relation, we propose a method that simultaneously extracts buildings and roads from remote sensing images. The accuracy of both tasks can be improved using our proposed multitask feature interaction (MFI) and cross-scale feature interaction modules. To be specific, a multitask interaction (MTI) module is proposed to interact information across building extraction and road extraction tasks while preserving the unique information of each task. Furthermore, a cross-scale interaction (CSI) module is designed to automatically learn the optimal reception field for buildings and roads under varied appearances and structures. Compared with existing methods that train individual models for each task separately, the proposed collaborative extraction method can utilize the complementary advantages between buildings and roads and reduce the inference time by half using a single model. Experiments on a wide range of urban and rural scenarios show that the proposed algorithm can achieve building-road extraction with outstanding performance and efficiency.