Remote Sensing Image Super-Resolution via Mixed High-Order Attention Network

Recently, remote sensing images have become increasingly popular in a number of tasks, such as environmental monitoring. However, the observed images from satellite sensors often suffer from low-resolution (LR), making it difficult to meet the requirements for further analysis. Super-resolution (SR) aims to increase the image resolution while providing finer spatial details, which perfectly remedies the weakness of satellite images. Therefore, in this article, we propose an innovative mixed high-order attention network (MHAN) for remote sensing SR. It comprises two components: a feature extraction network for feature extraction, and a feature refinement network with high-order attention (HOA) mechanism for detail restoration. In the feature extraction network, we replace the elementwise addition with weighted channelwise concatenation in all skip connections, which greatly facilitates the information flow. In the feature refinement network, rather than exploring the first-order statistics (spatial or channel attention), we introduce the HOA module to restore the missing details. Finally, to fully exploit hierarchical features, we introduce the frequency-aware connection to bridge the feature extraction and feature refinement networks. Experiments on two widely used remote sensing image data sets demonstrate that our MHAN not only obtains better accuracy than the state-of-the-art methods but also shows the superiority in terms of running time and GPU cost. Code is available at https://github.com/ZhangDY827/MHAN.