MIS-YOLOv8: An Improved Algorithm for Detecting Small Objects in UAV Aerial Photography Based on YOLOv8

Small objects’ detection from a drone’s perspective has always been a challenging issue in the field of object detection. To address the problems of low recognition accuracy and information loss in small object detection, this article proposed MIS-YOLOv8 algorithm, primarily aimed at resolving the issue of small object loss during the detection process of the classic YOLOv8s algorithm. First, a multilevel feature extraction (MFE) module was designed for enriching the feature representation capabilities capable of extracting objects from different scales. Second, a small object detection mechanism was incorporated for improving the detection ability. Finally, the integration of depthwise atrous flexible convolutions is introduced, enabling a rich capture of information from spatial to depth dimensions, thereby reducing the loss of small objects. The improved MIS-YOLOv8 algorithm validation was conducted on the VisDrone2019 dataset, where MIS-YOLOv8 demonstrated a 9% and 6.2% increase in mAP@0.5 and mAP@0.5:0.95, respectively, compared with YOLOv8s. The experimental results indicated that the improved model exhibits superior performance in small object detection for drones.