Jim Watters schrieb: > Pablo d'Angelo wrote: >> > If I understand correctly both models will align an image so it is on > the same plane as others.
After some more reading of the code, I'm quite sure that the tilt can only work well with rectilinear input images. If only that case is interesting, one doesn't even need angles, a simple 3x3 homography matrix transform is sufficient, and probably more stable than the tilt model. > The XYZ model calculates the position of the camera, this will cause > certain distortions to the image. XYZ have to be optimized with ypr. > The TxTyTzTs model calculates the actual distortion to align the image > after it has been placed correctly after optimizing ypr. I don't believe that ypr and the TxTyTzTs are independent. For the shift compensation, the TxTyTzTs model will also require simultanious optimisation of d and e. > The advantage to the XYZ model is it uses fewer overall parameters. > > But when I try imagine manipulating images in my head using TxTyTzTs i > don't see how Tz is any different than r. And maybe Tz it is not > necessary. The advantage to the TxTyTs model is ypr can be optimized > first to get a good placement before distorting the image by optimizing > TxTyTs overall needing fewer control points. You still need Tx, Ty, Ts and d,e. This assumes that you do not need to touch y,p,r from a previous optimisation. However, I think y,p,r will try to compensate for the parallax, and they will thus be quite wrong, in an attempt to rescue the situation. I'm not sure that a later tilt estimation works satisfactory with the previously estimated y,p,r parameters. Maybe one can get away, if the camera hasn't been moved too far. My experience with the tilt model was not so good. I have prepared a nice testset with the aerial images posted earlier, and it works quite well with the XYZ mode. I'll give more details later. 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 -~----------~----~----~----~------~----~------~--~---
