Andreas Hebeisen wrote:
When I print the evaluation image mentioned above, I don't get the blacks and shadow details I'm looking for on this matte paper. The problem already shows up in the softproof view of Aperture and remains when the (matte black) ink hits the paper. In the attached image, I've tried to visualize the problem. It contains a crop from the bottom left corner of the evaluation image with different profiles and render intent settings.
Hi,
it doesn't look to me like a problem with the Argyll profile. The black
patch
(131) has a value:
R G B X Y Z L a b
131 "Y15" 0.0000 0.0000 0.0000 2.3593 2.4032 1.8365 17.475 0.86838 1.4520
icclu -ff -ia -pl 2011_V6-0_3800mk_Epson-EMP_EMP_1440_0_8bit.icc
0.000000 0.000000 0.000000 [RGB] -> Lut -> 17.420737 1.009836 0.880059 [Lab]
so the profile forward behahaviour is pretty close.
Looking at the B2A tables:
colorimetric:
icclu -fb -ia -pl 2011_V6-0_3800mk_Epson-EMP_EMP_1440_0_8bit.icc
0.000000 0.000000 0.000000 [Lab] -> Lut -> 0.000000 0.000000 0.000000 [RGB]
perceptual:
icclu -fb -ip -pl 2011_V6-0_3800mk_Epson-EMP_EMP_1440_0_8bit.icc
0.000000 0.000000 0.000000 [Lab] -> Lut -> 0.000000 0.000000 0.000000 [RGB]
So you should be getting RGB black out from it.
Looking at the Eye-one profile:
icclu -ff -ia eyeone.icc
0.000000 0.000000 0.000000 [RGB] -> Lut -> 17.230917 0.746360 1.497665 [Lab]
colorimetric:
icclu -fb -ia -pl eyeone.icc
0.000000 0.000000 0.000000 [Lab] -> Lut -> 0.045577 0.071370 0.090313 [RGB]
which corresponds to:
~/src/problems$../argyll/icc/icclu -ff -ia eyeone.icc
0.045577 0.071370 0.090313 [RGB] -> Lut -> 18.378980 0.509345 -0.280716 [Lab]
Not perfect, but within a delta E.
perceptual:
/src/problems$../argyll/icc/icclu -fb -ip -pl eyeone.icc
0.000000 0.000000 0.000000 [Lab] -> Lut -> 0.000000 0.000000 0.000000 [RGB]
At a guess there is something odd going on with the CMM. Perhaps the
input profile black point is being treated oddly ? (Not unusual
when it comes to RGB/matrix profiles, and the various changes in the ICC
spec. in regards to this aspect). What happens if you use the sRGB
profile from the Argyll distribution as the source colorspace ?
Graeme Gill.
