for everybody's continued basecurve calibration pleasure i've pushed a
small c program to git master:
https://github.com/darktable-org/darktable/tree/master/tools/basecurve
which you can use to extract a basecurve from a raw + jpg pair. it takes a
lot less memory than the python script and will create an optimized fit to
only 8 control points (you can increase it from the cmdline if necessary).
it'll give you a line of code to insert into iop/basecurve.c to get a new
preset (after a recompile).
that said, the basecurve preset system already supports distinction by
maker and model (as well as iso if that ever matters). all we need extra is
the `only show for matching images' bit, or maybe auto-set it in case the
model is more specific than just the empty string.
cheers,
jo
On Wed, Aug 14, 2013 at 2:15 PM, Torsten Bronger <
[email protected]> wrote:
> Hallöchen!
>
> Ger Siemerink writes:
>
> > Torsten, Well done and it would be nice if you summarize the
> > workflow into a blog on darktable.org.
>
> I'm so glad if that file is closed ... ;-) Really, I'm a
> calibration Nazi but colour matrices and fisheye entry pupils are
> much more fun! And, this is tedious reverse engineering of
> something the vendors should simply publish.
>
> Speaking of vendors ... I prepared
>
> http://wilson.homeunix.com/basecurve/all_linear.png
> http://wilson.homeunix.com/basecurve/all_log.png
>
> > [...]
> >
> > Maybe stupid thought: how does the type of lens, protection filter
> > and automatic WB influence the result.
>
> As far as lens and filter are concerned, it depends on spectral
> dependence. If they just make the image darker as if the shutter
> speed was increased, they don't affect the measurement. Vignetting,
> TCA, and distortion impose no problems at all.
>
> WB should be set correctly when shooting for the basecurve. This is
> because the camera applies a colour matrix when generating a RAW,
> and we don't know this matrix. Thus, we cannot undo its effect.
> Therefore, we must try to get fully desaturated (aka greyscale) data
> into the colour matrix, because then it has no effect.
>
> > I remember a blog saying that the best time to take a picture was
> > at noon on a cloudless day.
>
> This has no significance here. ;)
>
> Tschö,
> Torsten.
>
> --
> Torsten Bronger Jabber ID: [email protected]
> or http://bronger-jmp.appspot.com
>
>
>
> ------------------------------------------------------------------------------
> Get 100% visibility into Java/.NET code with AppDynamics Lite!
> It's a free troubleshooting tool designed for production.
> Get down to code-level detail for bottlenecks, with <2% overhead.
> Download for free and get started troubleshooting in minutes.
> http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
> _______________________________________________
> darktable-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/darktable-devel
>
------------------------------------------------------------------------------
Get 100% visibility into Java/.NET code with AppDynamics Lite!
It's a free troubleshooting tool designed for production.
Get down to code-level detail for bottlenecks, with <2% overhead.
Download for free and get started troubleshooting in minutes.
http://pubads.g.doubleclick.net/gampad/clk?id=48897031&iu=/4140/ostg.clktrk
_______________________________________________
darktable-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/darktable-devel
