TIN-BASED ROBUST MOSAICKING OF UAV IMAGES WITH CONSECUTIVE IMAGE CONNECTION

Abstract. UAV image mosaicking could be divided into processing in an absolute space and in a relative space. Among them, the latter technique generates a mosaicked image using only UAV’s EOP (Exterior Orientation Parameters) without additional spatial data. Since this technique uses only images, it is easy to use, but sometimes exhibits unstable quality. In this study, we adopted the mosaicking in a relative space by introducing the TIN (Triangulated Irregular Network) structure for consecutive image connectivity. This method refines a point cloud and extracts optimal images for mosaicking as a pre-processing. After that, this generates a TIN, and performs triangular unit mosaicking and image unit mosaicking to produce a mosaicked image. We evaluated the proposed method with datasets acquired by fixed wing and rotary wing UAVs. We compared this method’s results with Pix4Dmapper’s and the previously developed method’s results. Through the experimental results, we were able to verify that this method was less affected by external factors such as ground topology and UAV status. Moreover, we could confirm this method reduced over-transformation, and mismatch of the junction area between images on mosaicked images. It showed stable quality despite of using only images. Through the above results, our method also showed similar performance to Pix4Dmapper.