  Many telepresence robots are equipped with a forward-facing camera for video
communication and a downward-facing camera for navigation. In this paper, we
propose to stitch videos from the FF-camera with a wide-angle lens and the
DF-camera with a fisheye lens for telepresence robots. We aim at providing more
compact and efficient visual feedback for the user interface of telepresence
robots with user-friendly interactive experiences. To this end, we present a
multi-homography-based video stitching method which stitches videos from a
wide-angle camera and a fisheye camera. The method consists of video image
alignment, seam cutting, and image blending. We directly align the wide-angle
video image and the fisheye video image based on the multi-homography alignment
without calibration, distortion correction, and unwarping procedures. Thus, we
can obtain a stitched video with shape preservation in the non-overlapping
regions and alignment in the overlapping area for telepresence. To alleviate
ghosting effects caused by moving objects and/or moving cameras during
telepresence robot driving, an optimal seam is found for aligned video
composition, and the optimal seam will be updated in subsequent frames,
considering spatial and temporal coherence. The final stitched video is created
by image blending based on the optimal seam. We conducted a user study to
demonstrate the effectiveness of our method and the superiority of telepresence
robots with a stitched video as visual feedback.
