Brent wrote: > Pablo, > Now that I think about it, there is something odd in the fact that > doing a multi-step optimization by changing which variables are > optimized works any better than a full optimization.
Maybe my explanation in the previous email was a bit misleading. What I meant is to start optimizing with optimizing two images (with good connections etc.), then add the third, optimize again, add the fourth etc. This is done by the incremental optimization in hugin. (Note that here, control points in the non-optimized images are ignored). > That is, if the > current solution is in a local minima with respect to 10 variables, > for example, then it will still be in a local minima if fewer than the > full number is optimized starting from that point. However, there might be other local minima, which can also be found by the optimizer, as its way though the solution space is changed, and some "shortcuts" might be blocked (such as modifying lens distortions and d,e shift to make images fit better during the first iterations), might send the iterative optimization into the wrong direction, from which it might be unable to recover. Then the first local minima of will be different, and thus later optimization with more parameters will also find another solution. > If there's a way > out of trap when optimizing a subset of the variables, then that same > way out is available when more variables are allowed to vary. Hmm, I don't think there are always ways of of local minimas, and adding some new parameters to the optimisation do not nessecarily mean that the previous local minima ceases to be one in the new parameter space. ciao Pablo --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ To post to this group, send email to hugin-ptx@googlegroups.com To unsubscribe from this group, send email to hugin-ptx-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/hugin-ptx -~----------~----~----~----~------~----~------~--~---
