SIGNet: A Siamese Graph Convolutional Network for Multi-Class Urban Change Detection

Detecting changes in urban areas presents many challenges, including complex features, fast-changing rates, and human-induced interference. At present, most of the research on change detection has focused on traditional binary change detection (BCD), which becomes increasingly unsuitable for the diverse urban change detection tasks as cities grow. Previous change detection networks often rely on convolutional operations, which struggle to capture global contextual information and underutilize category semantic information. In this paper, we propose SIGNet, a Siamese graph convolutional network, to solve the above problems and improve the accuracy of urban multi-class change detection (MCD) tasks. After maximizing the fusion of change differences at different scales using joint pyramidal upsampling (JPU), SIGNet uses a graph convolution-based graph reasoning (GR) method to construct static connections of urban features in space and a graph cross-attention method to couple the dynamic connections of different types of features during the change process. Experimental results show that SIGNet achieves state-of-the-art accuracy on different MCD datasets when capturing contextual relationships between different regions and semantic correlations between different categories. There are currently few pixel-level datasets in the MCD domain. We introduce a new well-labeled dataset, CNAM-CD, which is a large MCD dataset containing 2508 pairs of high-resolution images.

Automated summary

Detecting changes in urban areas is challenging due to complex features, fast-changing rates, and human-induced interference. This paper proposes SIGNet, a Siamese graph convolutional network, to address these challenges and improve the accuracy of urban multi-class change detection tasks. SIGNet combines joint pyramidal upsampling with graph convolution-based graph reasoning and graph cross-attention methods to capture contextual relationships and semantic correlations between different regions and categories. Experimental results demonstrate that SIGNet achieves state-of-the-art accuracy on various MCD datasets. Furthermore, a new well-labeled dataset, CNAM-CD, containing 2508 pairs of high-resolution images is introduced to the MCD domain.