[ptx] Hugin wishlist, RFC

[Pablo d'Angelo]

On Wed, 04 Feb 2004, Alexandre Jenny wrote:

> That's an interesting wish list ...
> Let's talk a little about it !
> 
> > 1. Band blending (or some other intelligent blending)
> > 
> >    Even with setting every capture parameter at my camera to 
> > some fixed value, I still end up having differently exposed 
> > images that hardly match up, even with large feathering. 
> > Adjusting brightness kills the blue sky in most images, 
> > adjust color paints them pink. Adjusting both does both.
> 
> Of course, it's the next part we have to work on (after finishing automatic
> Point creation).

Before we start with exposure compensation we have to tackle another lens
defect, namely vignetting. I found that my camera produces gray level
differences of ~ 40, if zoomed out.

The pano tools plugins have a simple p = b*r^2 * p  (where p=pixel value)
function to combat that effect. Hmm not sure if this is the best solution.
I've played around with that issue, by creating a "correction" image, and
adding it to the real images, but have received mixed results.

See also:
http://members.rogers.com/photocreations/lightfalloff/index.html

Other wise I agree with Alexandre.

> > 2. Incremental optimization
> > 
> >    I think Pablo started this already, and it definetely will 
> > easy panorama creation, especially for the beginners. This 
> > gets around the incremental manual "position estimation", and 
> > successive optimization afterwards.
> 
> Pablo is doing it.
> We can also think of implementing the hough transform in hugin to have a
> good starting point from
> the manually located controls points (The same hough transform as in sift
> for panorama).

Yes, I'll start to integrate that stuff in the next week or so. Having a
hough transform would be interesting as well :)

> > 4. "Horizon points"
> > 
> >    I find the idea of setting horizontal lines 
> > counter-intuitive. Maybe to straighten the top of a gate or 
> > building, but to straighten the horizon I think this is more 
> > intuitive: Allow the user to drop points where he expects the 
> > horizon ("horizon points"). This points, of which there have 
> > to be at least 2 are used for two things: anchoring the 
> > height to 0 degrees, and creating horizontal line control 
> > point pairs between them (invisible to the user). Most people 
> > have a very good idea where the horizon is located, even if 
> > its completely covered with buildings and trees and such 
> > (must be some evolutional thing).
> 
> In Realviz stitcher, they have such a function which is called horizontal
> line.

Hmm, with the incremental optimisation, it is easiest to set the anchor spot
and then optimise. On the other hand, one could also select the horizon in
the preview image, and move the images, a bit like it is supported by PTGui.

> > 6. "Camera profiles"
> > 
> >    My digicam (and I guess lots of others) use some screwed 
> > focal length (7.8mm to 24mm something) being "equivalent" to 
> > some 38mm camera. For use with hugin I have to use 38mm, but 
> > the EXIF information reads 7.8mm. I guess it would help most 
> > users to use some kind of "camera profile", where they can 
> > specify one time the focal length and later choose the camera 
> > profile to use, instead of doing manual adjustment everytime 
> > they import pictures.
> 
> ... No comment again ... 

Haven't implemented the lens database/camera profiles function yet.
Not enough time...

ciao
  Pablo
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