Learned local features for structure from motion of UAV images: a comparative evaluation

San Jiang, Wanshou Jiang, Bingxuan Guo, Lelin Li, Lizhe Wang
2021 IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing  
Unmanned aerial vehicle (UAV) images have become the main remote sensing data sources for varying applications, and Structure from Motion (SfM) is the golden standard for resuming camera poses. Matching local feature descriptors is the prerequisite for the accurate and complete orientation of UAV images. Recently, some newly proposed learned methods have been shown to outperform the hand-crafted methods, such as the SIFT (Scale Invariant Feature Transform) and its variants, and almost all
more » ... d methods have been trained and evaluated by using images from the internet with varying focal lengths and varying size. It is of interest to investigate the performance of these learned methods with their pre-trained models for feature detection and description in the context of the SfM-based orientation. Thus, this paper conducts a comprehensive evaluation of both advanced hand-crafted and newly proposed learned detectors and descriptors by using four UAV datasets. The performance of these selected methods is compared in the context of feature matching and the SfM and MVS-based (Multi-View Stereo) reconstruction. Experimental results demonstrate that the learned descriptors combined with the SIFT-like detectors can provide accurate and complete feature correspondences and achieve better or competitive performance in the SfM and MVSbased reconstruction. For UAV image orientation, the learned descriptors can be an alternative to the existing hand-crafted descriptors without their model re-training. The source codes of this evaluation would be made publicly available. is with the Provincial key laboratory of geo-information engineering in surveying, mapping and remote sensing,
doi:10.1109/jstars.2021.3119990 fatcat:2mtvs7onwzh4jdt7aqeb4jeuqm