Multitask semantic change detection guided by spatiotemporal semantic interaction

Semantic Change Detection (SCD) aims to accurately identify the change areas and their categories in dual-time images, which is more complex and challenging than traditional binary change detection tasks. Accurately capturing the change information of land cover types is crucial for remote sensing image analysis and subsequent decision-making applications. However, existing SCD methods often neglect the spatial details and temporal dependencies of dual-time images, leading to problems such as change category imbalance and limited detection accuracy, especially in capturing small target changes. To address this issue, this study proposes a network that guides multitask semantic change detection through spatiotemporal semantic interaction (STGNet). STGNet enhances the ability to capture spatial details by introducing a Detail-Aware Path (DAP) and designs a Bidirectional Guidance Module for Spatial Detail and Semantic Information for adaptive feature selection, improving feature extraction capabilities in complex scenes. Furthermore, to resolve the inconsistency between semantic information and change areas, this paper designs a Cross-Temporal Refinement Interaction Module (CTIM), which enables cross-time scale feature fusion and interaction, constraining the consistency of detection results and improving the recognition accuracy of unchanged areas. To further enhance detection performance, a dynamic depthwise separable convolution is designed in the CTIM module, which can adaptively adjust convolution kernels to more precisely capture change features in different regions of the image. Experimental results on three SCD datasets show that the proposed method outperforms other existing methods in various evaluation metrics. In particular, on the Landsat-SCD dataset, the F1 score (F1_scd) reaches 91.64%, and the separation Kappa coefficient improves by 17.68%. These experimental results fully demonstrate the significant advantages of STGNet in improving semantic change detection accuracy, robustness, and generalization capability.