Towards Detection of Sheep Onboard a UAV
This addresses the challenge of small object detection for agricultural monitoring using UAVs, but it is incremental as it applies existing methods to a new dataset.
The paper tackled the problem of detecting small sheep from UAV imagery at 80 m altitude, where sheep are only about 15 pixels across, and found that a UNet detector with a weighted Hausdorff distance loss function performed best in terms of accuracy and speed.
In this work we consider the task of detecting sheep onboard an unmanned aerial vehicle (UAV) flying at an altitude of 80 m. At this height, the sheep are relatively small, only about 15 pixels across. Although deep learning strategies have gained enormous popularity in the last decade and are now extensively used for object detection in many fields, state-of-the-art detectors perform poorly in the case of smaller objects. We develop a novel dataset of UAV imagery of sheep and consider a variety of object detectors to determine which is the most suitable for our task in terms of both accuracy and speed. Our findings indicate that a UNet detector using the weighted Hausdorff distance as a loss function during training is an excellent option for detection of sheep onboard a UAV.