Hi all, This description is correct. Note that align_image_stack was really written more like a proof of concept and is not really well optimized. Actually, the implementation of the normalized cross correlation in hugin is very basic and thus quite slow. Replacing it with a properly optimized version (I believe opencv has a nicely optimized correlator) would make both align_image_stack and the fine tune functionality much faster.
ciao Pablo Bruno Postle wrote > On Thu 28-May-2009 at 07:52 -0700, Tom Sharpless wrote: >> So align_image_stack does use local correlations, then generates CP's >> as a way of communicating the required alignment to other tools? > > It generates control points because it uses the hugin optimiser to > do the alignment (which is also why it accepts projection and field > of view parameters). > >> Is this done in such a way as to allow some warping as well as simple >> shifting in the final alignment step? > > The alignment uses the usual roll, pitch, yaw and fov distortion. > >> That is, are the CP's based only or mainly on local shifts? > > No idea, the image is divided up into a grid and a feature detector > tries to place an even distribution of points over the image area. > > In practice, with the -p option it behaves like a control point > generator that only works with stacked photos, but which produces > very few 'bad' points and which works very well with large exposure > differences. > --~--~---------~--~----~------------~-------~--~----~ 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 [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hugin-ptx -~----------~----~----~----~------~----~------~--~---
