Resolution Preserving and Utilization Network for Tiny Object Detection in Large-Size Remote Sensing Imagery

Efficient tiny object detection (TOD) in large-size remote sensing imagery (LSRSI) is particularly challenging in real-world remote sensing applications. We observe that as the input size of the remote sensing scene increases, TOD faces more severe foreground signal identification issues. To address this, we are the first to design a backbone network from the perspective of low-level spatial feature preservation and utilization, specifically for tiny object feature extraction in large-size remote sensing scene patches. The proposed architecture, referred to as the resolution preserving and utilization network (RPUN), demonstrates excellent foreground tiny object feature response identification ability when increasing the input size of remote sensing scenes, effectively maintaining detection performance comparable to that of smaller input slices. Additionally, we introduce GF2UBSv2, a large-scale panchromatic satellite imagery dataset focused on tiny urban bridge detection. Extensive experiments conducted on GF2UBSv2, DIOR, SODA-A, and DOTAv2.0 demonstrate the superior performance of RPUN compared with state-of-the-art methods. The code and dataset are available at: https://github.com//Nankle.