[ptx] autopano: first attempt at semi-automatic panorama stitching

[Yili Zhao]

Hi,
  some codes and papers' reference:
> The VIGRA library already contains a Harris corner detector.
I remember that Pablo said that citeseer doesn't contain the paper
"A Combined Corner and Edge Detector" in its database. 
You can find the paper and the Matlab code from 
       http://www.cs.uwa.edu.au/~pk/Research/MatlabFns/.

> Employ Lucas-Kanade optimization on the full image.
It seems that this algorithm needs some image pyramid processing.
The Matlab code and paper can be found from
       http://www.ri.cmu.edu/people/baker_simon.html,
and the C code and paper can be found from
       http://robotics.stanford.edu/~birch/klt/.

  Phase correlation can be used also to perform a coarse search,
then klt can be used to subpixel registration. The code can be 
found from
      http://home.freeuk.com/lyndonhill/pc.html.

Regards
Yili