Great Kay! I will try to compile it this time, the features of your pv are really compelling and would easy a lot to build great panoramas!
thank you! Luis Henrique Em ter., 5 de mai. de 2020 às 06:54, 'kfj' via hugin and other free panoramic software <[email protected]> escreveu: > Hi group! > > I've recently started this thread to point you to my image and panorama > viewer: > > https://groups.google.com/forum/#!topic/hugin-ptx/bj1g86oe6Wk > > In my initial posting, I've already mentioned the topic of 'live > stitching' - displaying a synoptic view of several registered source images > *without stitching*. I've made good progress along these lines, and the > latest version of pv can *directly read PTO files*. The file select dialog > will show PTO files, and it's as simple as opening them like any other > image file. On the command line, just pass a pto file like you'd pass an > image file, like > > pv pano.pto > > pv will only process the source image information ('i-lines'). pv supports > PTO geometry well: it will handle source images in rectilinear, cylindric, > spherical, fisheye and stereographic format and honour the source images' > orientation, horizontal field of view and all lens correction parameters. > Photometric parameters are ignored except for Eev - pv expects sRGB or > linear RGB images and does not handle colour profiles, nor does it do > vignetting correction or camera response curve processing. Nevertheless, > the display of a well-registered image set, especially with images taken > with fixed aperture and exposure time, will be pretty close to the stitched > result, especially with applied feathering. > > 'live stitches' have advantages and disadvantages, I'll start out with > some advantages: > > > - Access to the output is much more immediate, because the lengthy > stitching process is avoided. As long as your image set remains the same, > you can quickly reflect changes in the PTO file by simply pressing 'F1' in > pv, which will reload the PTO file and reuse the interpolators, which > otherwise take some time to set up. You can use pv as an 'external preview' > while working on the PTO in a stitcher like hugin, save work in the > stitcher and refresh pv to see the output straight away. > - Interpolation is done directly on the source images. This preserves > the full source image quality and resolution - you can, e.g., zoom into the > view like into the source images, without being limited to the resolution > you chose for the output of stitching, and without the images having been > geometrically transformed and then stored before being read back in again, > losing some quality in the process. Same goes for exposure. > - pv uses a geometric approach to select from which source image(s) a > target pixel should be taken. Without feathering or alpha processing, the > simple rule is: 'take from the source image whose center is closest to the > target pixel'. Seams are not explicitly defined but occur as an emergent > phenomenon. the 'closest-center' rule automatically chooses those parts of > the source images which are usually the best - technically speaking - > because they are least encumbered with lens flaws. > - You can experiment easily with several target projections (use > --target_projection=...), again without having to stitch an output image. > If you set up pv's viewer window with the right aspect ratio and use a > snapshot magnification appropriate to your desired output size, making a > snapshot of what you see is equivalent to stitching with a stitcher. The > process is WYSIWYG, and output quality is defined by output size and the > 'quality interpolator' which is currently in use (per default, a cubic > b-spline). It's much faster than 'true' stitching. The rendition of a > snapshot is delegated to a separate thread 'on the back burner', so you can > keep on viewing while the snapshot(s) are completed in the background. > > > Now for some disadvantages: > > > - 'live stitching' is memory-hungry. Every source image is read from > disk and converted to an internal representation (typically a set of two > float-based image pyramids). You can save on memory by passing > --build_pyramids=no, which will impose a few limits - for simply viewing > the PTO it's okay, though. But even then, more memory is needed than for > viewing a stitched panorama. > - There is - as of yet - no seam optimization. The seams occur where > two source images 'meet', and there is nothing you can do about it - > registration errors can be masked to a degree by using feathering, but > that's it. > - Animation can be slow. When viewing single images/panoramas, pans, > zooms, etc. should not stutter on a reasonably powerful system. But with > 'live stitching', frame rates drop. Especially when viewing views where > many source images contribute, and with target projections other than > rectilinear, frame rates may go down to a few per second. > > > This is a wide topic, so there are many more factors to consider, but I > won't go on here. What I'd like to mention is a second 'blending mode' > which pv offers. If you pass --blending=hdr, you can view registered > exposure series as if they had already been blended into an HDR output. > While pv has only rudimentary tonemapping (you might say it's only range > compression), this type of view still can give you a good idea about how > well-suited an image set is for HDR blending. There is no deghosting, > though. Making snapshots of hdr-blended views can preserve the full dynamic > range, provided the output format is capable of doing so - typically you'd > use openEXR output. So you can use pv to HDR-blend sets of images as well. > > Kay > > > > > -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/hugin-ptx/b478196a-a336-4743-998e-92ea72769820%40googlegroups.com > <https://groups.google.com/d/msgid/hugin-ptx/b478196a-a336-4743-998e-92ea72769820%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- Luis Henrique Camargo Quiroz http://luishcq.br.tripod.com - http://www.christusrex.org/www2/cantgreg http://panoramaslh.net/ -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/hugin-ptx/CAEKSoZa5S_TCFPFxt4AyjFyMhRb20iAm-1BCHTXhC3jCDK-G4g%40mail.gmail.com.
