Colour/brightness correction (was:hugin update)

[Pablo d'Angelo]

Welcome Alexandre,

> What's the problem ? It never take into account the constraint beetween
> picture 4 and 3. And you can see a major histogram distance is the
> debug.txt for such a case.
> It's not the good way to solve this problem. The solution would to
> create every histogram and solve a big problem of 4 * 256 variable with
> 4 constraints. And not 3 small 256 variable with 1 constraints. The
> neightboorhood solving is not the good way to do it. But the constraint
> calculation is good.

Yes, the idea of solving the system in a single step would probably be a
good solution. It would be interesting to have this in some future stitcher.

> with hugin. Every of you I think have read this
> http://www.cs.ubc.ca/~mbrown/panorama/panorama.html. That's exactly what
> I'm rewritting. I have already the SIFT feacture extractor.

Cool! 
it will be interesting how well it works with non rectilinear images too.


> My option is not to do a full panorama tools from picture
> to pano, but to generate a hugin or ptgui project directly with the good
> parameters. I called this project PtPrepros (panoTools preprocessor) and
> it should be available in a week or two.

Whow, thats really great.

> The only big issue I have is a
> licencing problem. I have to ask Dr Lowe for that.

Yep, just ask and see what he thinks. Does he have a patent on the sift
features?

> Next, I have some question. I rewriting my feature extractor in cpp
> (tested in matlab) and I'm willing to use vigra to do it (that would
> allow a direct use in hugin with no rewrite).

Ah, so you have a matlab version right now?

> But I go a strange problem
> with the library. After having a full install of everything needed for
> vigra, I run into a problem with the jpg library init. When I use this
> library it crashs, without, it's good. (I'm on windows 2k with visual
> studio .net). I checked with different version of the libjpeg with no
> luck. It seems to be in the library init before you get in the main
> function. Any idea ?

Strange. I haven't used the import/export of vigra, I'm just including
the header files. does the error also occur with the example applications
included in vigra?

If you need more help with vigra please let me know.

ciao
  Pablo
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