[argyllcms] Re: how to add patch around bw axis

If You add a plenty of gray patches manually, the OFPS places other patches 
automatically at certain distance from this gray column, the same way as 
distance between other OFPS patches. It's not a bug.
I do the next, for example 1323 patches:
1.
targen -v -d3 -g0 -s0 -f882 -c"Preprofile.icc" OFPS882
At this point I get spread of 882 patches. I think the one A4 for color 
characterization may be not enough. And 441 patch for gray axis is quite enough.
2. With the table processor (Microsoft Office Excel or Open Office Scalc) I 
generate the 441 gray patch analogously "OFPS882.ti1" file by the next manner:

883 0 0 0 0 0 0
884 0.227272727 0.227272727 0.227272727 0.2160325 0.227266116 0.247568802
885 0.454545455 0.454545455 0.454545455 0.432065 0.454532232 0.495137605
...
1321 99.54545455 99.54545455 99.54545455 94.622235 99.54255877 108.4351354
1322 99.77272727 99.77272727 99.77272727 94.8382675 99.76982488 108.6827042
1323 100 100 100 95.0543 99.997091 108.930273

The first value in row is patch number, the second-fourth - RGB values (from 0 
to 100 in each channel), the fifth-seventh values - XYZ values. Note, that XYZ 
values are need to targen if there will be automatic patch spread on a charts 
and to choosing right color for spacers between patches for automatic reading. 
This is a main reason to use pre-profile data for me.
Then I save this table as a text file, where the numbers separated by spaces. 
At this step I get my bespoke values for target.
3. I insert the text from the point above in the OFPS882.ti1 file after 882-nd 
patch but before END_DATA KEYWORD. One more change in *.ti1 is needed: I must 
change declared number of patches from 882 to 1323 - "NUMBER_OF_SETS 882" 
becomes "NUMBER_OF_SETS 1323".
Now I have the valuable target file with quality OFPS and a huge number of 
grays.
The next steps are standard: charts generation by printtarg (printtarg -v -m0 
-ii1 -t300 -p200x260 MY1323), printing and measuring. See sample files in 
attached archive.

I must say, that my real method is more complex: I do the table of Lab values 
which randomly speraded around Lab gray axis within certain radius from it, 5dE 
for example. Then I convert Lab to RGB by preliminary profile of my printer 
(icclu). Then I compute XYZ values for my RGB values by the same profile 
(icclu). Then both data sets, RGB and XYZ I insert in *.ti1. This way I get 
perceptually spreaded target values with corresponding XYZ. From that *.ti1 I 
generate charts without no spacers. I can print 720 patches on one A4 page for 
i1 instrument. Thanks to correct XYZ, the printtarg spread allows accurate 
strip reading of printed charts.

-----Original Message-----
From: Daniele Pennati <danielepennati@xxxxxxxxxxxxx>
To: argyllcms@xxxxxxxxxxxxx
Date: Thu, 30 Oct 2008 12:15:18 +0100
Subject: [argyllcms] how to add patch around bw axis


Hello
I'm new at argyll and at building printer profile... so, I'm sorry if  
I'll post stupid questions :-)
I have find out that if I use targen with default algorithm (OFPS) I  
didn't get any patch around the b/w axis so I have decided to use this  
command line:
./targen -v -d3 -g21 -f441 Target
I got the following distribution of patch:
http://www.danielepennati.com/download/default02.jpg
The problem is that I want a better fine tuning of bw axis and of the  
nearest colors, something like what you obtain with these tree  
different targets:
http://www.photoactivity.com/public/comersus6F/Dettagli/Profili/Cfrt  
Asse Grigio.jpg

I want to build a 882 patches test chart with argyll using the default  
command line ./targen -v -d3 Target and I want to add to this others  
441 patch around the bw axis... in this way I'll get a 1323 patch test  
chart (3 A4 with the i1)
here is the problem!!! How can I add these new patches?
I have made a tiff file using photoshop with the new 441 patches and I  
want to get his reference .ti1 file. In this way I'll be able to add  
the new 441 patches to the "old" 882 made by argyll...
How can I do this?
I tried to use the scanin command to build the .cht file and the .ti3  
file starting from my tiff test chart but I didn't able to do that...
I'll appreciate your advices!
sorry for my very bad english...
Thank
Daniele

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