[Digikam-devel] Patch: fix automatic correction of lens chromatic aberration

Matthias Welwarsky matze at welwarsky.de
Tue Mar 10 09:54:42 GMT 2009


On Tuesday 10 March 2009 09:14:43 Andi Clemens wrote:
> Ok so I'll wait for another update...

I think I've fixed it, but no time to test. Will post an update tonight.

>
> Andi
>
> On Tuesday 10 March 2009 08:56:48 Matthias Welwarsky wrote:
> > On Monday 09 March 2009 11:30:27 Andi Clemens wrote:
> > > I will take a look it the patch now...
> >
> > I've taken another look into it, seems its not complete yet. Geometry and
> > distortion correction also need subpixel access, and I've found that it
> > doesn't work any more if I check "16 bits color depth" in the "Raw
> > Conversion" settings.
> >
> > > Andi
> > >
> > > On Sunday 08 March 2009 19:51:12 Gilles Caulier wrote:
> > > > Matthias,
> > > >
> > > > Thanks a lots. this patch solve a task from my TODO list.
> > > >
> > > > This patch is a good candidate to go to 0.11 development branch and,
> > > > if it doesn't break i18n, in 0.10 (trunk) before finale release.
> > > >
> > > > Marcel, Andi, can you check this patch for me and guide Matthias on
> > > > the right way. I'm very busy here to prepare my evening classes
> > > > presentation for next Wednesday. To test, just use these pictures :
> > > >
> > > > http://digikam3rdparty.free.fr/TEST_IMAGES/LENSFUN/
> > > >
> > > > Thanks in advance.
> > > >
> > > > Gilles Caulier
> > > >
> > > > 2009/3/8 Matthias Welwarsky <matze at welwarsky.de>
> > > >
> > > > > Hello,
> > > > >
> > > > > the attached patch fixes CA correction in the lens auto-correction
> > > > > tool. The fix
> > > > > consists of two parts:
> > > > > 1.) set Alpha component of corrected pixel to "fully opaque",
> > > > > otherwise corrected image is not visible (trivial)
> > > > > 2.) Implement sub-pixel interpolation in class DImg, necessary for
> > > > > CA and CI
> > > > > correction with lensfun.
> > > > > There are two new pixel color accessor functions:
> > > > > getSubPixelColor() and getSubPixelColorFast(). The first one uses
> > > > > Lanczos interpolation to compute subpixel colors, the second one
> > > > > bilinear interpolation. Lanczos yields better
> > > > > results, but is a lot slower than bilinear. Before using
> > > > > getSubPixelColor(),
> > > > > prepareSubPixelAccess() needs to be called to precompute the
> > > > > Lanczos kernel.
> > > > >
> > > > > Lanczos implementation was adapted from ufraw, Bilinear was
> > > > > implemented according to Wikipedia description.
> > > > >
> > > > > I would be happy to hear comments on how to optimize the
> > > > > computation, it's probably not optimal yet.
> > > > >
> > > > > regards,
> > > > >         matthias
> > > > >
> > > > > _______________________________________________
> > > > > Digikam-devel mailing list
> > > > > Digikam-devel at kde.org
> > > > > https://mail.kde.org/mailman/listinfo/digikam-devel
> > >
> > > _______________________________________________
> > > Digikam-devel mailing list
> > > Digikam-devel at kde.org
> > > https://mail.kde.org/mailman/listinfo/digikam-devel
> >
> > _______________________________________________
> > Digikam-devel mailing list
> > Digikam-devel at kde.org
> > https://mail.kde.org/mailman/listinfo/digikam-devel
>
> _______________________________________________
> Digikam-devel mailing list
> Digikam-devel at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-devel




More information about the Digikam-devel mailing list