[argyllcms] Re: Print Validation
- From: <robert@xxxxxxxxxxxxxxxxxx>
- To: <argyllcms@xxxxxxxxxxxxx>
- Date: Mon, 20 Oct 2014 11:49:36 +0100
Yes, well I'm doing it as I show below, but Jan-Peter suggested another
approach (which he presumably thinks is better). The reason I'm interested
in going a bit further is that I would like to be able to generate a target
from an image (for example a single-color gradient) in order to check out
how well the profile is performing. If I could do that with targen I would
be very happy, but I don't see a way of doing it except manually (which I
REALLY don't want to do).
This is how I'm doing it at the moment and I'm getting dE2000K values of
under 1.0 (with an average of about 0.5), which I'm happy with (but then
again, I'm not sure I'm doing it correctly):
============================================================================
=========
targen -v -d2 -G -f100 iPFTest
copy iPFTest.ti1 iPFRef.ti1
printtarg -v -r -ii1 -a1.0 -T300 -M6 -pA4 iPFTest
cctiff -v -ir -e iPF6400_HP_ID_Satin.icm iPFTest.tif iPFTestO.tif
move /Y iPFTestO.tif iPFTest.tif
fakeread -v -Ir iPF6400_HP_ID_Satin.icm iPFRef
Pause Print iPFTest.tif using no color management.
chartread iPFTest
Pause The test results will be in iPFValidate.txt
colverify -v2 -N -k -s -w -x -L iPF6400_HP_ID_Satin.icm iPFRef.ti3
iPFTest.ti3 >iPFValidate.txt
============================================================================
========
Robert
_____
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Derin Korman
Sent: 20 October 2014 09:56
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: Print Validation
Aren't we over complicating this? You can print the original target you have
with the print profile you made applied to it (ie. İn color managed mode)
scan that target with your spectrophotometer, use that measurement as a base
to compare future prints readings via colverify. Make sure you average a
couple readings to account for user error and paper unevenness.
On 20 Oct 2014 06:08, "FreeLists Mailing List Manager"
<ecartis@xxxxxxxxxxxxx> wrote:
argyllcms Digest Sun, 19 Oct 2014 Volume: 11 Issue: 185
In This Issue:
[argyllcms] Re: Print Validation
----------------------------------------------------------------------
From: <robert@xxxxxxxxxxxxxxxxxx>
Subject: [argyllcms] Re: Print Validation
Date: Sun, 19 Oct 2014 21:34:08 +0100
Hi Jan-Peter,
I would like to try your suggestion but I don't understand how to. Just to
go through your steps:
1. Create Print Wedge in printer color space: OK, I can do that.
2. Create a test file with the same colors as the print wedge. I take it
you mean a .ti3 file and RGB colors? What do I do, list them in triplets
with a space in between each value and each triplet on a separate line?
What about headers etc? I have no idea how to do this and I can't find
anything in the documentation.
3. Convert the text file with fakeread to Lab. Do I not also need a .ti1
file for this? If I had both the .ti1 and ti3 files I guess I would use
something like fakeread -l wedge.ti3 wedge?
4. Print the wedge with color management off. OK, I think I can manage that
:)
5. Measure the print wedge. OK, I can do that too, but it would be a lot
easier to do if I could use chartread rather than spotread, and for that I
would need a .ti2 file.
6. Compare the results.
As you can see, I'm pretty well at sea here! I would be very interested to
try this, so if you have the time to give me some hints I would be very
grateful.
What would be really great would be to be able to produce a .ti1 file from a
tif file. Is there such a utility? (I can't find one, but it would be very
useful!).
Then most of the above could be automated.
Or, alternatively, just to create a .ti1 file (manually or by using targen)
and from that generate the .ti2 and .ti3 files using the normal commands,
fakeread etc.
I think I'm missing something because I don't understand why doing things by
hand is better than doing it using the Argyll commands (targen, printtarg,
cctiff, chartread, fakeread).
Robert
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Jan-Peter Homann
Sent: 18 October 2014 14:23
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: Print Validation
Hello Robert,
The proofing workflow Graeme is describing adresses normally a source
gamut which is smaller than the target gamut and an absolut colorimetric
match from source to target.
You are using AdobeRGB as a source, which has several colors, which are
out of gamut of the target colorspace (printer)
you also using the relative colorimetric intent.
...
If you want to test, how good matches a printer the printer profile:
create a a print wedge in the printer colorspace
(same colorspace you have the printer profile with)
create a text file with the same colors as the print wedge
convert the text file with fakeread to L*a*b*
print the print wedge in device mode mode (colormanagement off)
measure the print wedge
compare the measurement results with the fakeread output
Regards
Jan-Peter
Am 17.10.14 18:39, schrieb robert@xxxxxxxxxxxxxxxxxx:
> Hi Graeme,
>
> I've tried the workflow you've suggested (below) to check my print
accuracy
> and my results are well off. Here are the first few (worst values):
>
> No of test patches = 100
> File 0 Chose patch 1 as white, xyz 0.964203 1.000000 0.824905
> File 1 Chose patch 1 as white, xyz 0.837679 0.872949 0.741557
> L*a*b* white reference = XYZ 0.964200 1.000000 0.824900
> 21: 18.038560 25.951478 22.489887 <=> 39.803954 11.831945 -35.079664 de
> 37.269236
> 28: 34.185591 -67.085881 -6.455341 <=> 62.944388 -90.026713 44.587042 de
> 34.884374
> 41: 40.524868 -33.803806 -52.438105 <=> 65.223756 -60.678084 -21.994298
de
> 29.777970
> 26: 52.908776 -78.403017 -17.947748 <=> 71.957265 -79.305174 41.137194 de
> 29.656735
> 12: 57.830887 -42.597937 -57.500006 <=> 76.080635 -62.957608 -8.243975 de
> 27.776304
>
> So I'm clearly doing something drastically wrong!
>
> I would really appreciate it if you would have a look at these commands to
> see where the mistakes:
>
>
> targen -v -d2 -G -f100 iPFTest
> copy iPFTest.ti1 iPFRef.ti1
>
> fakeread -v -Ir iPF6400_HP_ID_Satin.icm iPFRef
>
> printtarg -v -r -ii1 -a1.0 -T300 -M6 -pA4 iPFTest
> cctiff -v -e AdobeRGB1998.icc iPFTest.tif iPFTestO.tif
> move /Y iPFTestO.tif iPFTest.tif
>
>
> Pause Print iPFRef.tif using iPF6400_HP_ID_Satin.icm profile and Rel. Col.
> chartread iPFTest
>
> Pause The test results will be in iPFValidate.txt
> colverify -v2 -N -k -s -w -x iPFRef.ti3 iPFTest.ti3 >iPFValidate.txt
>
> I'm printing iPFTest.tif using Photoshop, RelCol to
iPF6400_HP_ID_Satin.icm.
>
>
> Many thanks!
>
> Robert
>
>
> -----Original Message-----
> From: argyllcms-bounce@xxxxxxxxxxxxx
[mailto:argyllcms-bounce@xxxxxxxxxxxxx]
> On Behalf Of Graeme Gill
> Sent: 15 October 2014 14:26
> To: argyllcms@xxxxxxxxxxxxx
> Subject: [argyllcms] Re: Print Validation
>
> robert@xxxxxxxxxxxxxxxxxx wrote:
>
>> I've tried your first method and it's just fine. I'll try the variation:
> is
>> that effectively equivalent to using profcheck?
>
> Yes, it's going to be similar.
>
>> I don't really understand your last suggestion.
>
> In a proofing type workflow, the aim is to get a printer (or other
> display device) to emulate some particular target colorspace. You do
> this by transforming the colors you want to reproduce through a source
> profile (which defines the target you are trying to emulate) and the
> device profile.
>
> If you want to check how accurate your proofing system is,
> then the type of thing you might do is generate a test
> set in the target device colorspace, and run it through the
> source profile with fakeread to create the reference .ti3 file.
>
> Then you run the same colors through your proofing workflow
> (e.g. create a .tif using printtarg, then apply the source
> to printer device link to the .tiff using cctiff and print it,
> or run the .tif through whatever ICC based workflow you have
> setup for proofing), measure the result and compare
> the .ti3 to the reference using colverify.
>
> Graeme Gill.
>
>
>
>
>
--
homann colormanagement ----------- fon +49 30 611 075 18
<tel:%2B49%2030%20611%20075%2018>
Jan-Peter Homann -------------- mobile +49 171 54 70 358
<tel:%2B49%20171%2054%2070%20358>
Herzbergstr. 55 FG 3.01 -- http://www.colormanagement.de
10365 Berlin ---------- mailto:homann@xxxxxxxxxxxxxxxxxx
------------------------------
End of argyllcms Digest V11 #185
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