On 17 Dez., 08:09, Pablo d'Angelo <pablo.dang...@web.de> wrote: > If you want to try the hugin vignetting correction, one needs to know > corresponding pixels between the overlapping plates. There are two > possibilities: > > 1. Add support for the input image (plate) format to hugin, and write a > script that creates a PTO file from the metadata in the plate files. > Then the standard workfow could be used (on the x64 images). The > corresponding parameters could then be used for radiometric correction > of the individal plates. If we add the toast projection, to panotools, > it would be possible to directly output toast, otherwise its possible to > produce corrected plate images.
I think that's a good path for now; the pto should be easy to make - I've had a look at the attached metadata and it does look like it's all there (wish all the other incoming images were only half as well documented - these astronomers sure are precise...) > Looking athttp://porpoisehead.net/images/dss_blend_needed.jpg > I'm a bit sceptical how well it might work with hugins vignetting > correction though. so am I > Do you know if the position of the plate in the > telescopes focal plane is available in the metadata? Do you have a > document describing the metadata? I my notion of astronomy isn't wrong, I suppose it's one plate at a time right bang in the middle where the focal point of the mirror is. Center of image = optical axis, which should be normal to the image plane. Then leave the plate there for an hour with the telescope slowly rotating to make up for the earth's rotation, then next plate - as long as the night lasts and there are no clouds. Matthew, please correct me if I'm wrong. > For a first experiment, a smaller subset of the mosaic would be > sufficient, maybe a 5x5 grid. For this test, the alignment could be done > in hugin to avoid the steps I have mentioned before. The full data will > be a real challange, even when using the tiny images. I disagree. At the lowest resolution, so at x64, the total amounts to a measly 161 Megapixels, transfer volume much less since the JPGs are quite cruelly compressed [this surprises me - I'm almost certain the true source data would not be JPG and the pyramids at hand are already a few steps down the processing pipeline...] The real work is writing the script from the metadata. Also it seems to me that the problems are more pronounced in some areas than other. Best to have the full x64 set. > The full mosaic would be much simpler, if we had a "reference image" > that covers the whole mosaic. It only needs to contain the "background" > brightness, not all the stars etc. This would make the "vignetting" > correction much simpler and probably yield a nicer result. We would have that if we stitched together the x64 tiles, and since they are so precisely located, this stitch should come out really well. with regards 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 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
