Spherical Mosaics: Regular and Stereoscopic

[View this Stereoscopic Panorama with Red-Blue Stereo Glasses]


Traditional mosaicing methods use narrow field of view cameras to acquire image data. This poses problems when computing a complete spherical mosaic. First, a large number of images are needed to capture a sphere. Second, errors in mosaicing make it difficult to complete the spherical mosaic without seams. Third, with a hand-held camera it is hard for the user to ensure complete coverage of the sphere. This projects presents two approaches to spherical mosaicing. The first is to rotate a 360 degree camera about a single axis to capture a sequence of 360 degree strips. The unknown rotations between the strips are estimated and the strips are blended together to obtain a spherical mosaic. The second approach seeks to significantly enhance the resolution of the computed mosaic by capturing 360 slices rather than strips. A few different slice cameras are proposed that map a thin 360 degree sheet of rays onto a large image area. This results in the capture of high resolution slices despite the use of a low resolution video camera. A slice camera is rotated using a motorized turntable to obtain regular as well as stereoscopic spherical mosaics.

Publications

"Motion Deblurring using Hybrid Imaging,"
M. Ben-Ezra and S.K. Nayar,
IEEE Conference on Computer Vision and Pattern Recognition (CVPR),
Vol.I, pp.657-664, Jun, 2003.
[PDF] [bib] [©]

"360 x 360 Mosaics: Regular and Stereoscopic,"
S.K. Nayar and A.D. Karmarkar,
Panoramic Vision, pp.291-307, R., Springer-Verlag, Apr, 2001.
[bib] [©]

"360 x 360 Mosaics,"
S.K. Nayar and A. Karmarkar,
IEEE Conference on Computer Vision and Pattern Recognition (CVPR),
Vol.2, pp.388-395, Jun, 2000.
[PDF] [bib] [©]

Images

  360 x 360 Mosaic:

This mosaic was captured with a single rotation of the slice camera shown below.

     
  360 x 360 Stereo Mosaic:

These pictures show the left and right spherical mosaics obtained by off-center rotation of the slice camera. Also shown are perspective left and right views for two parts of the scene. Notice the disparities between the left and right views.

     

Videos

If you are having trouble viewing these .MPG videos in your browser, please save them to your computer first (by right-clicking and choosing "Save Target As..."), and then open them.

  Slice Camera:

The slice camera is a catadioptric camera that captures a very thin 360 degree slice with high resolution. When the camera is rotated about the center of the captured slice, it produces a single 360 x 360 mosaic. When it is rotated off-center, it produces two 360 x 360 mosaics that together form a stereoscopic spherical mosaic.

     
  Slice Camera Output:

The slice camera maps a thin 360 degree slice onto a large disc in the image. Even though the detector of the camera has low resolution (640x480 pixels) the mapping performed by the slice camera allows one to compute a high resolution slice of the world.

     

Slides

CVPR 2006 presentation     With videos (zip file)

Catadioptric Cameras for 360 Degree Imaging

Applications of 360 Degree Cameras

Catadioptric Stereo: Planar and Curved Mirrors

Generalized Mosaicing