On 4 Mrz., 20:36, xraycrystallographer <[email protected]> wrote:
> One thing that I remain “fuzzy” on is the optimization process using > the control points. From my playing around it appears that an > increase in the number of control points results in a better fit of > the images Let's put it this way: if you're working with a good panorama head, a well-calibrated lens and make no mistakes, you can get away with as little as two control points per image, because then you just have to nudge the correct data into the right spot. If you're using an uncalibrated lens freehand, generating lots of control points may give you what looks like a better fit, but in fact it's just massaging your data within the degrees of freedom the mathematical model permits. It's cheeting - but you may get away with it. The main problem with freehand shooting is parallax, and you can't get rid of parallactic errors, no matter how many CPs you have. the main problem with badly calibrated lenses is that you need lots of CPs to figure out the lens geometry for every panorama you make. There's one situation where you really want lots of CPs, and that's for lens calibration. > 1) In the preview window, allow the user to generate an area which > would locate the corresponding areas in the various individual images > to search for additional control points. This is a nice idea. I have something along these lines in the pipeline, but it's not quite there yet. For now you may use this feature: if you select images in the images tab and then call the control point generators, only CPs between the selected images will be found. If you perform this step with the CPG set to larger scales (parameters like --maxdim NNNNN or --fullscale, depending on which CPGs you use) you will get more CPs for your difficult areas. > 2) Allow the user to pick a control point that is “fixed” during the > optimization process. The control points are fixed once they're set. the coordinates in the images they refer to will not change by optimization. Only the image positions, lens parameters etc. will change through optimization. If you want to fix a whole image, you can make that the 'position anchor'. And, in the optimizer tab, if you select user-defined optimization, you can switch on and off individual parameters to optimize to your heart's content. Kay 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 [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hugin-ptx
