Syncra, Stitching mosaics with Hugin is "advanced" but perfectly feasible. The key requirement is that all your control points are on one reasonably flat plane. Just enable viewpoint optimization. With care and determination you can get excellent alignments of many tiles. I regularly stitch mosaics of 10-20 pictures of flat wall paintings.
Some tips: the correct alignment may be rather unstable and Hugin is likely to find wildly incorrect ones, so be prepared to edit CPs, reset and re-optimize a lot. Best to use calibrated lens parameters and not optimize those. The pano you are after will appear to have been taken from very far away with a very long lens, so set the pano projection to rectilinear, and if Hugin thinks the FOV is over 20 degrees, fight back (for example by setting an artificially long input lens focal length). Alignment can fail catastrophically if even a few CPs are wrong or not on the plane, and sometimes you have to add pictures one by one, optimizing each time. It helps if you can define some straight line CPs across many or all the images. In the case of aerial photos, the ground might not be flat enough or you might not be able to see enough of the flat ground to set an adequate number of CPs. And of course, unless taken from a high altitude, buildings, trees, etc. will not align with the ground -- you have to route your stitching seams between things that stick up, rather than across them. That may or may not be possible, and if possible it may require some planning to get the right shots. But it is not so hard, I think; for example Google Maps is paved with low level aerial mosaics, which show few obvious "stitching glitches" although if you look close you can see the buildings leaning in various directions. Good luck! -- Tom On Apr 22, 4:31 am, kfj <[email protected]> wrote: > On 21 Apr., 20:25, Syncra <[email protected]> wrote: > > > I am new to Hugin and I am wondering how powerful this software could be to > > stitch together aerial photos in order to reproduce a detailed map of a > > large area. > > > The input photos would be taken by a UAV in a kind of matrix where each > > photo should overlap with the following. How can this process be automated? > > You're not the first one to ask this. There is one big problem with > aerial photos, and that's parallax. If your landscape is flat, you're > working from great altitude, you shoot in quick succession, or your > lens is very long (or several of these combined), the problem may be > small enough to ignore, but usually it isn't. And AFAICT the people > who come up with the idea to stitch aerial photos eventually find that > they can't produce parallax-free image sets and therefore give the > whole idea a miss. > > If you have a parallax-free image set, you stitch it as a mosaic. This > means you optimize for X, Y, Z and r instead of the usual y, p, r. If > your shots are all taken from the same height you can leave out the Z. > Do a manual trial and see if you can work around the parallax problem > and if you get a good result. There's little point thinking about > automation before you've established that. > > Kay -- 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
