Re: Stereo panoramas

[John Goodman <jgood@xxxxxxxx>]

WILLIAM D SCHWADERER wrote:

> I just do not get the over/under approach versus the
> side-by-side...

Stereopsis depends on small disparities or differences between 
two views presented simultaneously (and individually) to our 
two eyes, usually in the form of relative left-right displacements 
among objects in the viewed space. (Just alternately close one 
eye and notice how various objects in the scene "shift.") We 
have left and right eyes, not upper and lower, and twin-lens 
stereo cameras have left and right lenses, as do stereo viewers 
and projectors. If you use a twin-lens stereo camera in portrait 
orientation with the lenses above and below, the only way the 
resulting stereo pair could be conveniently viewed would be to 
orient the pair vertically and your eyes in the same over and 
under fashion as when the image of the scene was captured.  

I understand how over and under panoramas of a scene taken 
with two cameras displaced only vertically have disparities in 
the two views that can yield stereo information. What I don't 
understand is how these could be seen as normal via our 
horizontally displaced eyes and perceptual expectations. I really 
would like to know the details of the periscope viewer 
mentioned previously. Also, it's certainly not trivial to display 
panorama prints on the inside of a large cylinder with the 
observer comfortably at the center.

A very interesting "binocular panorama" was mentioned on the 
QTVR list, and I quote:

> Date: Tue, 03 Oct 2000 02:16:45 -0400
> From: Denis <denis@xxxxxxxx>
> Subject: Binocular Panorama
> 
> Hi,
> 
> I just finished my first excusable attempt at binocular
> panoramas. Two (different) panos are presented side by side in a
> Director environment and navigation control is achieved through
> the right pano. Unless you can rig a stereoscope to your
> monitor, you will have to free fuse to see the result.
> 
> http://www.gunt.com/download/BinoPan.sit (Mac - 2.9 MB)
> http://www.gunt.com/download/BinoPan.zip (PC - 3.1 MB)
> Please read the ReadMe file for details.

If you have the bandwidth/time to get the archive, just run the 
executable (it's a stand-alone viewer). "Free fuse" means use 
parallel-eyes or cross-eyed freeviewing techniques. The result is 
very effective and great fun, though there is room for 
improvement.  

Fwiw, the link to another QuickTime stereo pano now seems 
to come up Not Found, but I probably have a copy of the file 
somewhere. This was taken with a Roundshot 220VR, iirc, and 
requires red/green glasses to view in stereo. Afaik, this was also 
produced with a horizontal, not vertical, displacement base.  

John Goodman