  Six degrees-of-freedom (6-DoF) video provides telepresence by enabling users
to move around in the captured scene with a wide field of regard. Compared to
methods requiring sophisticated camera setups, the image-based rendering method
based on photogrammetry can work with images captured with any poses, which is
more suitable for casual users. However, existing image-based rendering methods
are based on perspective images. When used to reconstruct 6-DoF views, it often
requires capturing hundreds of images, making data capture a tedious and
time-consuming process. In contrast to traditional perspective images,
360{\deg} images capture the entire surrounding view in a single shot, thus,
providing a faster capturing process for 6-DoF view reconstruction. This paper
presents a novel method to provide 6-DoF experiences over a wide area using an
unstructured collection of 360{\deg} panoramas captured by a conventional
360{\deg} camera. Our method consists of 360{\deg} data capturing, novel depth
estimation to produce a high-quality spherical depth panorama, and
high-fidelity free-viewpoint generation. We compared our method against
state-of-the-art methods, using data captured in various environments. Our
method shows better visual quality and robustness in the tested scenes.
