A special lense and mirror allows to take a 360 degree photo. To the left,
you see the actual picture, the camera has taken.
The picture above is the same, but in a different coordinate system. |
Here is an example, where it is useful to know a bit of calculus or linear algebra.
Because there is no unwrapping tool available for 360 degree movies, I had to write
an unwrapper for movies myself. Reverse inegeneering the transformation was done
by taking a few dozen points, note their coordinates in both pictures and find
an interpolating map using curve fitting. I wrote the unwrapper as a C application.
It is extremely fast. It turned out that the 360 mirror is done
in such a way that the correspondence is given by an adaptation of polar
coordinates. Having available an unwrapping tool, the movie can be transformed by splitting sound
and picture, transform each picture and finally gluing together sound and picture again.
Below you see to the left the movie taken by the camera and to the right the unwrapped
movie. This was the first test. It needs still some tweeking. I still did not manage to
coordinate sound and pictures completely yet for example.