SEAMLINE OPTIMIZATION FOR UAV IMAGE MOSAICKING USING GEOMETRY OF TRIANGULATED IRREGULAR NETWORK

Abstract. For efficient UAV (Unmanned Aerial Vehicle) image monitoring, it is essential to mosaic multiple UAV images into one seamless image. In a mosaicked image, relief displacement of terrain is a major source of error. It is difficult to form seamlines that avoid all areas of relief displacements. A seamline determination method alone is limited in reducing the mismatch error on mosaicked image. In this study, we constructed a TIN (Triangulated Irregular Network) using tiepoints generated by rigorous bundle adjustments. We detected the regions where relief displacement occurred using the slope of TIN facets. It was found that the error of mosaicked image were mostly on TIN facets with high slopes. Our method generated a mosaicked image after elimination of error-prone region and showed that the distortions were effectively removed. This study showed that the proposed method could produce mosaicked images with stable quality using geometric clues of TIN. We expected that our method can be used for UAV image mosaicking robust to mismatching factors.