[argyllcms] Re: dcraw linear workflow?

  • From: Klaus Karcher <lists@xxxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 14 Sep 2009 11:46:37 +0200

Klaus Karcher wrote:
In my experience (with scanner profiles), the low self-fit error of XYZ CLUT profiles can be deceptive.

Although the self fit error of Lab CLUT profiles is higher, they can perform better than corresponding XYZ profiles when one uses independent test- and trainingset (see example below):

a) testset == trainingset:

profcheck -k TI3/combined.ti3 ICC/combined_Lab.icc
Profile check complete, errors(CIEDE2000):
max. = 9.178650, avg. = 1.371444, RMS = 1.841394

profcheck -k TI3/combined.ti3 ICC/combined_XYZ.icc
Profile check complete, errors(CIEDE2000):
max. = 8.111750, avg. = 0.939068, RMS = 1.496107

b) testset <> trainingset:

profcheck -k TI3/testset.ti3 ICC/trainingset_Lab.icc
Profile check complete, errors(CIEDE2000):
max. = 9.018731, avg. = 2.481812, RMS = 3.028049

profcheck -k TI3/testset.ti3 ICC/trainingset_XYZ.icc
Profile check complete, errors(CIEDE2000):
max. = 21.973729, avg. = 2.892268, RMS = 4.078021

supplement:

c) testset == trainingset (b):

profcheck -k TI3/trainingset.ti3 ICC/trainingset_Lab.icc
Profile check complete, errors(CIEDE2000):
max. = 8.683593, avg. = 1.309224, RMS = 1.785959

profcheck -k TI3/trainingset.ti3 ICC/trainingset_XYZ.icc
Profile check complete, errors(CIEDE2000):
max. = 7.524726, avg. = 0.878769, RMS = 1.397771

----

trainingset(b): ColorChecker SG, basICColor dcam target, Kodak Q13 Grayscale and several self-made targets (inkjet- and laserprints)

testset(b): self-made oil paint target

Klaus

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