Object detection in UAV imagery based on deep learning: Review

Object detection is one of the key technologies in improving the autonomous sensing ability of Unmanned Aerial Vehicles (UAVs). Research on object detection is of critical significance in UAV applications. Compared with traditional methods based on manual features, deep learning based on the convolutional neural network has a powerful capability of feature learning and expression, therefore becoming the mainstream algorithm in object detection. In recent years, object detection research has achieved a series breakthrough in the field of natural scene and the research in UAVs has increasingly become a hotspot simultaneously. This paper reviews the research progress of object detection algorithms based on deep learning, summarizing their advantages and disadvantages. Then, some typical aerial image datasets and the method of transfer learning are introduced, and relevant algorithms are analyzed aiming at the complex background, small and rotating objects, large fields of view in UAV imagery. The existing problems and possible future development directions are finally discussed. © 2021, Beihang University Aerospace Knowledge Press. All right reserved.