[argyllcms] Re: Determining proper error value for -r

  • From: "Roberto Michelena" <colorsync@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 24 May 2006 09:17:40 -0500


That's not what I would recommend. If you're going to print 8000
patches, you're better off using them to explore the color space
in more detail, not just repeating the same test patches.

But the key here is to do it only for situations of repeatedly profiling similar devices. I agree that it wouldn't make sense for a one-off, but consider this hypotetical (but quite realistic) scenario: - I sell proofing systems based on Epson K3 devices and two different papers (one gloss, one semimatte) - "relinearization" over a canned (or prebuilt) profile does not cut it for producing precise matches - so I find myself forced to do a complete profiling of each system I install

now consider this:
1) on my office ("base system") I measure 8 repetitions of a
1000-patch target, which builds a 'reliability' map of the colorspace
2) then I measure an 8000-patch target (standard not repeated patches)
3) I build a "base" profile with this 8000-patch measurements and the
"colorspace tolerance" map
4) I build a link profile (-G) between this "base" profile and ISOCoated
(maybe steps 3 and 4 could be combined)

so now my "base system" in my office has the best possible calibration
to ISOCoated
I have to repeat this for each paper type, of course; so twice.

Then everytime I install a system at a customer, I print and measure a
1000-patch chart through the "base" (canned) simulation, run it
through Refine, and use the produced abstract profile to recreate step
(4) and get a personalized link profile.
Either "refine" or "icclink" would have to incorporate usage of the
reliability map.

sounds good to me :)

-- Roberto Michelena
  Lima, Peru

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