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

[Bruno Postle]

On Thu 01-Jan-2004 at 11:50:53PM +0100, Pablo d'Angelo wrote:
> 
> has anyone tried the current autopano program?

Anonymous CVS is normally a few hours behind, so that might not be
buildable yet [*].

I tried it on a couple of single-row hand-held panoramas, it seemed
relatively fast.

The control points it created were nearly correct, but they were all
slightly wrong.  They were near enough though - If there was a
feature in hugin to select control points and redo the
auto-alignment, they would have been fixed.

I had an idea about this whole thing, the ultimate problem is that
automatically matching features in two images is very sensitive to
differences in rotation and distortion - It's going to perform very
badly in edge cases like wide-angle lenses and hand-held photos.

However, if you have a photo that contains 'features' and you know
roughly the type of lens and fov, there is an attribute that is
independent of roll, pitch and yaw that can be calculated precisely:
The angular distance between any two features in a single image.

Say you have an image with three features; there will be three of
these angles that can be calculated - If another photo has three
features with the same three angles, then the two photos are quite
likely to actually correspond at those points.

Don't know if this is the theory behind any of the other approaches,
but calculating angles and comparing numbers is simple and very
fast.

[*] I've updated the hugin fedora1 RPM to include autopano, can't do
the redhat9 RPM today.

-- 
Bruno