[FFmpeg-devel] Vignette filter limitations...

[Evert Vorster]

Hi there.

The program's name is nona, and it is distributed in source code form with
Hugin.
http://hugin.sourceforge.net/docs/manual/Nona.html

The source code and descritpions is available here:
http://hugin.sourceforge.net/docs/html/index.html

I hope it helps?

On 27 August 2017 at 13:35, Paul B Mahol <onemda at gmail.com> wrote:

> On 8/27/17, Evert Vorster <evorster at gmail.com> wrote:
> > Hi there.
>
> Hi,
>
> >
> > I have asked this question on the ffmpeg-users list, but it's been oddly
> > quiet on this front.
> >
> > I am trying to create a ffmpeg command line that re-maps and stitches
> > together footage from the Samsung Gear 360 camera. The basic methodoly
> can
> > be applied to any 360 view camera. The reason I am doing this is that the
> > software that is available to do this is closed source and extremely
> > expensive. For a hobbiest, this is a bad situation.
> >
> > First thing I do, is to load a specially crafted series of frames in
> Hugin,
> > and perfectly map the lenses.
> > Then I make the remap files that the ffmpeg remap filter uses with nona
> -c.
> > I hand craft a alpha map to do the blending between the lenses, and the
> > results are really good.
> >
> > Unfortunately I have a real problem with vignetting.
> > The vignette filter in ffmpeg seems to have some room for improvement.
> > In Ffmpeg there is only one variable, and the x,y center. This allows for
> > only one type of vignetting correction with the "backward" option set.
> >
> > In Hugin (and the panotools) the lens is described with 3 variables, and
> an
> > x,y center. This enables the vignetting strength to be described as a
> > custom curve.
> >
> > If you are curious about the project, this is the github page, with
> > examples.
> > https://github.com/evertvorster/dualfisheye2equirectangular_ffmpeg_remap
> > There are example .pto files, that when loaded in Hugin show the lens
> > chataristics of the Samsung Gear 360 lenses, and some sample footage to
> > test on.
> >
> > How difficult would it be to port the panotools' vignetting correcting
> > filter into ffmpeg?
>
> How it is actually named?
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>



-- 
Evert Vorster
Isometrix Acquistion Superchief