Multiview Graph Convolutional Hashing for Multisource Remote Sensing Image Retrieval

Recently, hashing has been successfully applied for large-scale remote sensing image retrieval (LSRSIR) due to its advantage in terms of computation and storage. In LSRSIR, existing hashing methods mainly focus on single-source remotely sensed data. They cannot effectively fuse multisource remotely sensed data, which has a large potential for LSRSIR. To fulfill this gap, this letter proposes a novel deep hashing method, dubbed Multiview Graph Convolutional Hashing (MGCH) that can successfully fuse multisource remote sensing image. Since graph convolutional network (GCN) has been applied as an effective means that expresses and integrates relationships into features, MGCH applies a GCN to explore inherent structural similarity among multiview data, which will help to generate discriminative hash codes. An asymmetric scheme is developed that optimizes the proposed deep model in an end-to-end manner to improve training efficiency. We evaluate the proposed method by fusing two different kinds of RS images, i.e., multispectral (MUL) image and panchromatic (PAN) image. The experimental results on the dual-source RS image data set (DSRSID) show that the proposed MGCH outperforms state-of-the-art multiview hashing methods.