A movie consists of a succession of pictures shot rapidly (30 per second). We will only consider the vertical central line (1 pixel thick), that we'll call the scanline. When slowly rotating the camera, each frame will be like the last one, but very slightly shifted. So the scanline will sweep the whole scene.
Being in the center of the frame, the scanline will have no lateral barrel distortion. The scanline will also be very well horizontally aligned (relative to the rotation axis).
In order to collect more vertical pixels (i.e. to have a taller scanline, hence a higher vertical resolution), the camera is rotated by 90°. This rotation will have to be taken into account during the post-processing.
In summary, there are two phases:
Enough theory, now let's test this principle
Capture: The first part consists of shooting the movie in slow and continuous rotation. It only needs a camera able to shoot video clips, and a motorized rotating mount.
Post-processing: The second part needs a computer program. It consists of extracting the central column of pixels (corresponding to the scanline) from each movie frame, and stitching them together to form the panorama image.
So if you want to experiment too, you must be (for now) familiar with computer command-line tools:
the installation of command-line tools,
the operation of command-line tools,
the edition of script files, to tweak some parameters.
I will only provide instructions for experienced such users, and not
how to get acquainted to the command line.
Tested on Linux (Ububtu) and Mac OSX so far.
But, upon popular request, I may write a user-friendly program that anybody can user.