UAV image stitching by estimating orthograph with RGB cameras

In the field of image stitching, cases with large camera optical center movement and large parallax have been the virgin territory of research. The goal of image stitching is to overcome the parallax and stitch a natural image. We look into this problem in the context of ultra-low altitude flight of a UAV. We model the 3D world in this scenario and quickly estimate orthographic projection by pairs of homography matrices. Our stitching method can achieve precise alignment since it takes parallax well into consideration. The stitching results are natural and the extra time consumed is short.