[argyllcms] Re: An argyllcms version of the TC.918 target.

  • From: "Lars Tore Gustavsen" <lars.tore@xxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 11 Feb 2008 14:07:46 +0100

On Feb 11, 2008 1:22 PM, Roger Breton <graxx@xxxxxxxxxxxx> wrote:
> Hello Lars,
> I'd be interested in looking at your adaptation of TC9.18. But before I do,
> I'd like to understand why it is presumably superior to a an
> Argyll-generated ti1 RGB target using a similar number of patches.
> Perhaps we could start by a VRML of TC9.18? If such thing is available. And
> then a VRML of some Argyll chart? That way, we would have some "logical" way
> to compare both targets.
> I always believed that the spacing of the patches within an Argyll target
> was superior and therefore, could result in superior profiling. But if you
> think that the Atkinson target knows something that Argyll does not know
> about characterizing a printer RGB space then I say we all try to learn from
> it.
> Best regards,
> Roger Breton

Sorry for not clearing that up that. I'm sure Gill's targen command is
quite superior. But I don't think the rest of the world knows this.
Let say someone in the local photo club asks me, if I can profile
their printer. And I ask them, should I use a world class self made
printer target or one that rest of the world use. I guess most of them
will prefer the "rest of the world" version, especially when they know
my world class operating system.  :-)
I would continue to use targen myself and recommend  it to others.  My
starting point was more it nice to have the possibility to read those
"standard" targets. It is also a part of my learning process.

The creation of the  target was quite simple. I downloaded the
colorlab utility. It runs on my linux box with wine. I read in the
reference file and created a custom layout for it.

And back to the target, something is terrible wrong. :-) I have
created a reference file for the freely available profilemaker
measurements tool. I have installed this on one of the computers at my
work.  It only works in left right direction with my ref file, but I
get a deltaE about 0.05 better than argyll. I guess this confirm that
my file is not so bad created, but maybe I can tweak the ti2 file a
little more. I have added the files to the above address.

profile –v  read_by_chartread (sample-luster.ti3)
profile check complete, peak err = 4.363661, avg err = 0.938499

profile –v read_by_profilmaker (sample-profilemaker.txt )
profile check complete, peak err = 3.614479, avg err = 0.882414

Lars Tore Gustavsen

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