On Fri, Jul 29, 2016 at 12:24 PM, Torsten Bronger <[email protected]> wrote:
> Well, I accept data created with this tool in Lensfun's database but > I don't recommend it. In most cases, getting lines running across > the whole image *in one segment* is tricky. Mostly, the tool can > detect only multiple fragments of lines. One can play with the > parameters, or one can pre-edit the image (enhance contrast) but > then the convenience advantage is lost. YMMV. Absolutely YMMV and something to use with care. I found that even with tuning parameters it was much faster than the manual method, and I needed the contrast enhancement for my own eyes. The manual method also seemed fairly sensitive to exactly how careful I was in line placement (3 lines x 50 control point pairs each takes a long time!) and tended to diverge badly at small R. My thought (and you've been doing this a lot longer than I!) is that it's worth getting some good data through the centre of the image just to help anchor the fit there...otherwise degrees of freedom in the fit will go into fitting little wiggles of the periphery rather than keeping things reasonable at the center. Limiting to poly3 may have the same effect for lenses where that's appropriate. Incidentally, am I correct in assuming that despite the order of operations in lensfun itself (http://lensfun.sourceforge.net/manual/corrections.html), each element of the calibration process is independent? I.e. I don't need to have the correct distortion parameters in place to do vignetting or TCA? Didn't look like it in the script.... ------------------------------------------------------------------------------ _______________________________________________ Lensfun-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lensfun-users
