CDS-Net: Contextual Difference Sensitivity Network for Pixel-Wise Road Crack Detection

Road crack detection is a key computer vision task that identifies and locates cracks in road surface images, which usually have an irregular shape and contain only a few pixels in width. Generative and unsupervised methods are popular these years, but generative methods require a lot of training data and computational power while unsupervised methods are not so satisfactory in pixel-level segmentation. The process is challenged by the irregularity of crack shapes and complex road image backgrounds. To alleviate these problems, we propose a novel method in this paper, CDS-Net, that significantly improves road crack detection performance through multiple practical modules, including the Multi-Directional Hierarchical Attention (MDHA) module and the Difference Sensitivity Reconstruction Block (DSRB). Specifically, the MDHA module employs a multi-directional feature extraction strategy to capture detailed information of cracks, thereby enhancing the discriminative power of the features. The DSRB module, designed to address the inefficiency of traditional skip-connections, utilizes masked convolution and graph convolution attention to reconstruct and refine feature representations. Additionally, we propose an improved weighted cross-entropy loss function to address the inherent class imbalance problem in road crack detection. Extensive experiments on five public datasets demonstrate that CDS-Net achieves superior performance compared to other state-of-the-art methods, showcasing its effectiveness and robustness in road crack detection. It also has a stronger generalization ability compared with other methods. Code is available at https://github.com/ttttqz/CDS-Net/tree/master.