[argyllcms] Re: Characterizing a scanner using Argyll
- From: Gerhard Fuernkranz <nospam456@xxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Mon, 02 Feb 2009 23:52:01 +0100
Klaus Karcher wrote:
> Klaus Karcher wrote:
>> I've also seen abruptly and dramatically increasing errors with Lab
>> CLUT scanner profiles, most notably in the shadows.
>
> here a numeric example
There are pretty low L* numbers - was this a reflective medium or film?
Could you add the corresponding .ti3 as well?
-Gerhard
> Klaus
> ------------------------------------------------------------------------
>
> colprof -v -y -qh -D"LabCLUT" scanner
> ...
> profile check complete, peak err = 13.135772, avg err = 1.877744
> mv scanner.icc LabCLUT.icc
>
> colprof -v -y -qh -as -D"shaperMatix" scanner
> ...
> profile check complete, peak err = 66.673073, avg err = 6.134379
> mv scanner.icc shaperMatix.icc
>
> icclu -ir -ff -s255 -pl shaperMatix.icc < shadows.txt
> 26.000000 23.000000 23.000000 [RGB] -> MatrixFwd -> 5.078098 -0.800313
> 1.386871 [Lab]
> 25.000000 22.000000 22.000000 [RGB] -> MatrixFwd -> 4.625271 -0.679537
> 1.157508 [Lab]
> 24.000000 21.000000 21.000000 [RGB] -> MatrixFwd -> 4.187122 -0.559044
> 0.925442 [Lab]
> 23.000000 20.000000 20.000000 [RGB] -> MatrixFwd -> 3.778328 -0.439119
> 0.687971 [Lab]
> 22.000000 19.000000 19.000000 [RGB] -> MatrixFwd -> 3.399629 -0.335309
> 0.516691 [Lab]
> 21.000000 18.000000 18.000000 [RGB] -> MatrixFwd -> 3.044775 -0.274084
> 0.330967 [Lab]
> 20.000000 17.000000 17.000000 [RGB] -> MatrixFwd -> 2.709740 -0.163351
> 0.115780 [Lab]
> 19.000000 16.000000 16.000000 [RGB] -> MatrixFwd -> 2.398919 -0.102978
> -0.078051 [Lab]
> 18.000000 15.000000 15.000000 [RGB] -> MatrixFwd -> 2.105531 -0.021879
> -0.270067 [Lab]
> 17.000000 14.000000 14.000000 [RGB] -> MatrixFwd -> 1.839113 0.029870
> -0.436208 [Lab]
> 16.000000 13.000000 13.000000 [RGB] -> MatrixFwd -> 1.590128 0.102345
> -0.600534 [Lab]
> 15.000000 12.000000 12.000000 [RGB] -> MatrixFwd -> 1.365357 0.124460
> -0.743504 [Lab]
> 14.000000 11.000000 11.000000 [RGB] -> MatrixFwd -> 1.169942 0.146008
> -0.891880 [Lab]
> 13.000000 10.000000 10.000000 [RGB] -> MatrixFwd -> 0.991960 0.188281
> -1.038439 [Lab]
> 12.000000 9.000000 9.000000 [RGB] -> MatrixFwd -> 0.826270 0.201488 -1.156422
> [Lab]
> 11.000000 8.000000 8.000000 [RGB] -> MatrixFwd -> 0.689935 0.214127 -1.279810
> [Lab]
> 10.000000 7.000000 7.000000 [RGB] -> MatrixFwd -> 0.568648 0.218709 -1.370103
> [Lab]
> 9.000000 6.000000 6.000000 [RGB] -> MatrixFwd -> 0.473961 0.201715 -1.470320
> [Lab]
> 8.000000 5.000000 5.000000 [RGB] -> MatrixFwd -> 0.382029 0.205729 -1.566018
> [Lab]
> 7.000000 4.000000 4.000000 [RGB] -> MatrixFwd -> 0.317438 0.172620 -1.600043
> [Lab]
> 6.000000 3.000000 3.000000 [RGB] -> MatrixFwd -> 0.267153 0.147001 -1.672570
> [Lab]
> 5.000000 2.000000 2.000000 [RGB] -> MatrixFwd -> 0.231917 0.113325 -1.712001
> [Lab]
> 4.000000 1.000000 1.000000 [RGB] -> MatrixFwd -> 0.211358 0.079364 -1.754134
> [Lab]
> 3.000000 0.000000 0.000000 [RGB] -> MatrixFwd -> 0.203461 0.008564 -1.731892
> [Lab]
> 2.000000 0.000000 0.000000 [RGB] -> MatrixFwd -> 0.200706 -0.012444 -1.736411
> [Lab]
> 1.000000 0.000000 0.000000 [RGB] -> MatrixFwd -> 0.197950 -0.033453 -1.740930
> [Lab]
> 0.000000 0.000000 0.000000 [RGB] -> MatrixFwd -> 0.197950 -0.033453 -1.740930
> [Lab]
>
> icclu -ir -ff -s255 LabCLUT.icc < shadows.txt
> 26.000000 23.000000 23.000000 [RGB] -> Lut -> 5.420270 -0.455171 0.103356
> [Lab]
> 25.000000 22.000000 22.000000 [RGB] -> Lut -> 5.018135 -0.524011 -0.001961
> [Lab]
> 24.000000 21.000000 21.000000 [RGB] -> Lut -> 4.613181 -0.591212 -0.098024
> [Lab]
> 23.000000 20.000000 20.000000 [RGB] -> Lut -> 4.196762 -0.681407 -0.174734
> [Lab]
> 22.000000 19.000000 19.000000 [RGB] -> Lut -> 3.724769 -0.944844 -0.182772
> [Lab]
> 21.000000 18.000000 18.000000 [RGB] -> Lut -> 3.241719 -1.205445 -0.192002
> [Lab]
> 20.000000 17.000000 17.000000 [RGB] -> Lut -> 2.851675 -1.484875 -0.162227
> [Lab]
> 19.000000 16.000000 16.000000 [RGB] -> Lut -> 2.652584 -1.779023 -0.134526
> [Lab]
> 18.000000 15.000000 15.000000 [RGB] -> Lut -> 2.475281 -2.093380 -0.168762
> [Lab]
> 17.000000 14.000000 14.000000 [RGB] -> Lut -> 2.260044 -2.454906 -0.209762
> [Lab]
> 16.000000 13.000000 13.000000 [RGB] -> Lut -> 2.040134 -2.817349 -0.275625
> [Lab]
> 15.000000 12.000000 12.000000 [RGB] -> Lut -> 1.829433 -3.132467 -0.352974
> [Lab]
> 14.000000 11.000000 11.000000 [RGB] -> Lut -> 1.621837 -3.428162 -0.438847
> [Lab]
> 13.000000 10.000000 10.000000 [RGB] -> Lut -> 1.411609 -3.727643 -0.551953
> [Lab]
> 12.000000 9.000000 9.000000 [RGB] -> Lut -> 1.197040 -4.026350 -0.682687 [Lab]
> 11.000000 8.000000 8.000000 [RGB] -> Lut -> 0.982917 -4.320353 -0.821843 [Lab]
> 10.000000 7.000000 7.000000 [RGB] -> Lut -> 0.778940 -4.609260 -0.991925 [Lab]
> 9.000000 6.000000 6.000000 [RGB] -> Lut -> 0.670556 -4.858263 -1.261866 [Lab]
> 8.000000 5.000000 5.000000 [RGB] -> Lut -> 0.561573 -5.102973 -1.546697 [Lab]
> 7.000000 4.000000 4.000000 [RGB] -> Lut -> 0.451419 -5.335355 -1.857764 [Lab]
> 6.000000 3.000000 3.000000 [RGB] -> Lut -> 0.339857 -5.572372 -2.167710 [Lab]
> 5.000000 2.000000 2.000000 [RGB] -> Lut -> 0.228322 -5.794601 -2.497762 [Lab]
> 4.000000 1.000000 1.000000 [RGB] -> Lut -> 0.114414 -6.014235 -2.838676 [Lab]
> 3.000000 0.000000 0.000000 [RGB] -> Lut -> 0.000000 -6.224093 -3.196122 [Lab]
> 2.000000 0.000000 0.000000 [RGB] -> Lut -> 0.000000 -6.905165 -3.491483 [Lab]
> 1.000000 0.000000 0.000000 [RGB] -> Lut -> 0.000000 -7.596359 -3.781664 [Lab]
> 0.000000 0.000000 0.000000 [RGB] -> Lut -> 0.000000 -8.298692 -4.077104 [Lab]
>
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