Hi Kay,

I typically add as many CP as I can and after the first alignment I
will delete those that are definitely bad.  Usually, there will be
many points with errors of several thousand pixels.  You can usually
see a distribution change between normal and outliers.  After this, I
will set the Nadir to a unique lens number and iteratively opimize
everything and remove outliers.  I will inspect a sample of the
outliers to make sure they are really bad each time.  In some
situations, cloud movement will cause good points to have higher
errors, so I am careful not to delete too many good points.  I can
usually get a defect free stitch with a 21mm lens using this
technique, but I agree there are probably simpiler methods.

Regards,
Rick

On Dec 27, 7:48 pm, kfj <[email protected]> wrote:
> On 27 Dez., 12:20, RueiKe <[email protected]> wrote:
>
>
>
> > The project did use a pano head, so all stacks will be aligned with
> > the exception of the nadir, which may have some slight movement, so I
> > add control points to align the Nadir and specify a different lens
> > after the intial alignment.  I am still using autopano-sift-c.  Yes, I
> > use a lot of control points then delete many during the processes of
> > successive optimizations.  I can usually acheive about 0.3 pixel mean
> > error for a 16k wide pano.
>
> You may loose more than you gain by throwing out a great number of
> CPs. Often the 'best' CPs are clustered in unproblematic areas,
> particularly if you are using a fisheye and/or the lens isn't
> perfectly calibrated. If you just throw out everything above a
> threshold, you may end up with insufficient area coverage. Don't be
> too keen on minimizing the mean error, it's not a measure for the
> quality of your final panorama, just an indicator about the CPs. In my
> experience it is useful to throw out only CPs which are obviously way
> off or wrong (like, the worst 10%, or everything above 10). The
> optimizer is a very clever thing and can well cope with outliers.
>
> Kay

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