SFD-DETR: an end-to-end spatial–frequency dual-guided multi-scale network for tiny object detection in UAV aerial images
摘要
Object detection in unmanned aerial vehicle (UAV) imagery is challenging due to extremely tiny object sizes, complex backgrounds, and large scale variations. To address these challenges, we propose an end-to-end spatial–frequency dual-guided multi-scale network for tiny object detection in UAV aerial images (SFD-DETR). First, we propose a lightweight Multi-Scale Channel Separation (MSCS) feature extraction network to enhance representation efficiency while reducing model complexity. Furthermore, we propose a Spatial–Frequency Enhancement Module (SFEM) to preserve fine-grained spatial details and improve tiny object discriminability through adaptive global–local feature recalibration. In addition, we employ a frequency-adaptive upsampling operator, Converse2D (C2D), together with the Shape-IoU loss to mitigate high-frequency detail loss and improve bounding box regression. Experiments on the VisDrone and HIT-UAV benchmarks demonstrate that SFD-DETR achieves 39.4% and 83.1%