On 1/31/22 11:41, johnfi...@gmail.com wrote: > The most important use case for this idea would also depend on support for > low priority control > points, which IIUC is in a fork of Hugin that I haven't had time to look at > yet. > > Assume that control points are very accurately placed, but still don't > optimize very well. So the > remapped images don't align very well. For high contrast areas, anything > worse than a single pixel > of misalignment is a very poor alignment. The usual Hugin answers to that > seem to be based on > avoiding blending high contrast areas. Sometimes that is a good solution. > Sometimes it isn't. > > One cause of major misalignment is the combination of translation (moving the > point of view between > images, rather than using a tripod with a perfectly adjusted nodal slide) > with subjects of the photo > being at significantly varying distance.
That happens to me a lot because of my shooting style. Any time I see an interesting scene I'll shoot a pano sequence, and it's almost always hand held, much less a pano head (which I don't even have). And to make matters more fun, there's often both near-field and distant objects. > The translation optimization necessarily depends on all connections between > two images (including > indirect connections through other images) being at the same distance from > the camera. For multiple > subject distances, there is no correct remapping for translation. My way of dealing with that is to shoot lots of extra shots, throw out all of the near field control points, and then use masks to ensure to the degree possible that only one frame will contain the offending (close) object. When I can't do that, I either have to accept the problem, crop the panorama down, or not use it. It's a somewhat tedious process, because I have to build it many times, but usually I manage to get something clean enough. I have on occasion resorted to manually warping the result in GIMP, which is really tedious. > Assume either user action (or maybe some automation I haven't though of) > lowers the priority of all > control points that connect two images at other than the most important > subject distance. Then the > alignment for that distance is great, but other distances are a problem. > > If high contrast important features at other than the preferred distance are > continuous beyond the > width of an image, there is no decent solution: warping would distort the > shape, while any other > approach would blur the seams. I'd have to see examples of what the distortion would look like. > Some reshaping is fundamentally necessary for that combination of viewpoint > shift plus > multi-distance. Blurring across a seam can concentrate the reshaping where > it matters least. But > in many cases I think warping would do a better job with less user effort. If I understand what you're saying, yes. -- A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ --- You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. To unsubscribe from this group and stop receiving emails from it, send an email to hugin-ptx+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/hugin-ptx/c2c73353-f787-b82c-aa7e-7c75a9073a06%40alum.mit.edu.
