so, it would be an interesting thing to create a template.pto before, and include it in the ASIFT source code, and see what happens??
On Mon, Nov 1, 2010 at 9:02 AM, Tom Sharpless <tksharpl...@gmail.com> wrote: > Hi Bernd > > On Oct 31, 7:02 am, Bernd Hohmann <hohm...@harddiskcafe.de> wrote: > > On 31.10.2010 03:14, Tom Sharpless wrote: > > > > Tom, > > > > > It is a fact that SIFT does not find as many matches as we would like > > > in wide angle and especially fisheye images. But that problem will > > > not be solved by better matching of affine transformations, as it is > > > due to image deformations, characteristic of those lenses, that are > > > not affine transformations. > > > > As far as I can see, ASIFT is doing its job very well even with fisheye > > images and without calibration data. > > > That is surprising to me. As I understand the description of ASIFT > (which is not very well) it assumes that the source images are in > rectilinear projection. I do agree with Morel and Yu's idea that > simulating rotations of the direction of view should improve local > similarity measured at true match points. However the results of that > rotation do depend on the lens projection function, so I would not > expect such a good result when the wrong lens function is used. > However, the results should speak for themselves. > > In panoramic image sets, the images are in fact related by pure > rotations of the view direction (leaving aside parallax errors). > Therefore, if lens distortion is corrected, the Morel/Yu procedure > should generate locally almost identical images, when the chosen > rotations happen to equal the true ones. By using the approximate > alignment angles from a "shooting template", it should be possible to > limit the range of angles that needs to be searched; and of course > also to limit the image areas that need to be searched. This could > lead to a rather fast alignment algorithm. > > Regards, Tom > > > Bernd > > > > -- > > Bernd Hohmann > > Dipl. Organisationsprogrammierer > > DV Sachverständiger & Gutachter > > Höhenstrasse 2 * 61130 Nidderau > > Telefon: 06187/900495 * Telefax: 06187/900493 > > Blog:http://blog.harddiskcafe.de > > -- > 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<hugin-ptx%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/hugin-ptx > -- 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
