On Wed, 10 Nov 2010 22:51:06 -0500, Yuval Levy wrote: > > On November 10, 2010 10:19:35 pm Robert Krawitz wrote: >> One more panorama from the trip last month: >> http://rlk.smugmug.com/Other/Landscapes/4851912_oeCNm#1086043156_p4b23 > > nice work, thanks for sharing.
Thanks. >> Hugin kept giving me FOV estimates of between 87 and 95 degrees HFOV > > don't worry, as long as it is < 360° (i.e. fits on the panosphere) > for partial (non 360° panos) accuracy of estimated HFOV is much less > important than the visual result. That's good to know (this is referring to the lens HFOV -- the overall pano HFOV was getting estimated anywhere between 270 and 355 degrees). >> The amount of error was truly extreme -- the worst CP was about 85 >> units off and the average was 8 units. However, there were only a >> couple of bad seams when I actually stitched it together, and they >> were all in locations that were fairly easy to fix. Interestingly, >> when I added more CPs, the worst error went down to 70, but there >> were more seams. I guess the thing to worry about is what happens >> when it's stitched, not what the optimization results are (Yuv, I >> guess that's what you were telling me :-) ). > > yep, you guess right! in this particular case, parallax affects the > lower 1/3 of the image more than the top 2/3. If I was to add CPs > manually, I would only put them on the far away mountains and maybe > on the far away trees. The CP generator does not know this. It > does not have a sense for depth, and it does not know that CPs at > infinity suffer much less from parallax than CPs in proximity of the > camera's viewpoint. Interesting. When I added more CPs to get a broader distribution, I got lower error numbers and narrower seam errors but more seams -- and in more difficult locations. I particularly tried to add CPs far away, but they didn't help. I got the best results by simply killing the obvious bad CPs and relying on the auto points. > points in the lower 1/3 will have higher error. the > cleaning/pruning function of CPs in Hugin may or may not catch them > - depending on where the majority of the points are found. running > it multiple times (i.e. clicking the button multiple times) may help > or may make things worse. > > the random/regular pattern on the surface of the rock makes it very > easy to deal with bad seams in your favorite image editor. Yup. The harder part was where the seams crossed the cracks in the rock. I can't even tell where the seams are on the surface of the rock. If the bad seams crossed through trees it would have been much harder. Fortunately I didn't wind up with a seam crossing my shadow. This is all definitely a lot of fun. I probably won't be doing a lot more panos this year -- 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
