[argyllcms] Re: Support for ColorSavvy Mouse 2 spectrophotometer



Graeme Gill napisaÅ(a): 
I usually use the ss setting for generic charts. Use the -a option in
printtarg to create specific patch sizes.
Wow, it what I need. I didn't find this option before... 

There are a number of conversion tools already. See if logo2cgats (for
instance) can be altered to work with the Color Mouse files. If you send
me some example files (the .ti1, .ti2 and the Color Mouse CSV file), I
can look at this.
File can contain measurement in XYZ, Lab, LCh, Luv, xyY, Yxy, uvY,Yuv (3 numbers), values can be from 0 to 100 or from 0 to 1. Line prefix, suffix and numbers separating symbol (eg.: ',' or ' ') can be any character or string. I generated file like this:
82.51,85.45,74.63
82.33,85.30,74.60
82.45,85.40,74.66
...
It contains exactly 216 lines, one line for patch. Then I merged this file with it1 file from Argyll (with changed header) using OpenOffice. Disadvantage is that patches has to be in right order (A1, A2...B1, B2... etc) so I use '-r' option for 'printtarg'.

Another option with non-supported instruments is to use the
printread -x mode, where you can feed in the Lab or XYZ value for each patch.
It can help with a little shell script to convert file to N runs of 'printread'. I think, I can write such script and post it on this mailing list.

3. Finally I do all the tasks manually using OpenOffice Calc and other tools, results are a bit better than with scanner and Kodak Q60 color target ;-) But IMO print are still too warm. It's my personal opinion, but I looking for option to manipulate white balance with argyll. Can I force profiler to generate "cooler" profiles?

I went through the exercise of comparing an (RGB) profile for my Epson 1800
generated using an IT8 chart and my Epson 4990 scanner, and the profile
using the SpectroScan. Now I did cheat slightly in that the Kodak IT8
chart had a custom reference file for it, but the results were remarkably
similar (on gloss paper). Subtly different, but hard to pick apart.
Exactly, difference is very subtle but visible (scanner results are less smooth). However results are equally warm with scanner and with spectrophotometer, a bit too warm, or maybe it's due to not my home illumination (not really proper for color work)?! I scan target and chart in RAW mode with 16x software oversampling using VUE Scan. Results from spectrophotometer are more smooth, even they use only 20% (216 vs 1026) of patches used with scanner. 

Unfortunately I haven't made any "creative" or manual color tools
for Argyll - the main intent has been to do everything by the numbers.
If I were to add a tweak control, the question is, what should it do ?
If a curve was applied down the neutral axis, what shape should it have ?
What colorspace should it be in ?
Hard to answer, but maybe You can add 'profile' switch/option to change WB up/down in Kelvin degree. It is possible?

My other findings is that I can change illuminant in spectrophotometer from D50 (default) to D55/D65/D75/A/C/F2/F7/F11/F12. It's not possible to change it with scanner workflow. BTW changing illuminant from D50 to D55 and remeasure pinted chart makes new profile "warmer" than profile made with D50 illuminant, am I right? So still I can't get "cooler" profile?!

I have been trying to collect a small set of charts that have been read with
scanners and with a spectrometer, to at least give me something to go
on in answering the above questions with regard to correcting the sorts
of neutrality errors that arise using a scanner.

The idea would be to have a test chart (or a program that generates a test
chart) of neutral and near neutral patches, labelled with their delta E
from ab 0,0, print them out with (the new) cctiff through the profile in
questions, and then pick the most neutral patch by eye, and feed those
numbers into "profile" as correction factors. It's pretty easy for
RGB, it's a bit more tricky for CMYK, because there have to be two
sets of numbers, one for low K, and another for high K.

Hmmm... so maybe you can add this option only for RGB profiling?! It's a bit selfish but my printer supports only RGB printing mode ;-)

regards,
MikoÅaj Tutak

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