Would anyone have a sample IT8 reference file for loading under darktable-chart > reference value tab?
I have tried many formats to no avail, and can’t find any relevant discussion here or on the web.
This is the content of my ColorChecker.txt file I try to load :
Thanks. Here’s the header and the first two row of data of one such Wolf Faust reference file :
IT8.7/1
ORIGINATOR “Wolf Faust”
DESCRIPTOR “Fujichrome Provia/Astia Type 3, L* a* b* (light D50, viewing angle 2)”
MANUFACTURER “Wolf Faust - http://www.coloraid.de”
CREATED “February 22, 2002”
PROD_DATE “2002:02”
SERIAL “F020430 Batch Average Data”
MATERIAL “For Fujichrome Provia and Astia Films”
KEYWORD “MEAN_DE” # Mean Delta E of samples compared to batch average
NUMBER_OF_FIELDS 17
BEGIN_DATA_FORMAT
SAMPLE_ID XYZ_X XYZ_Y XYZ_Z LAB_L LAB_A LAB_B LAB_C LAB_H STDEV_X STDEV_Y STDEV_Z STDEV_L STDEV_A STDEV_B MEAN_DE STDEV_DE
END_DATA_FORMAT
NUMBER_OF_SETS 288
BEGIN_DATA
A1 2.10 1.82 1.25 14.49 8.10 3.06 8.66 20.70 0.06 0.05 0.03 0.26 0.23 0.31 0.41 0.46
A2 2.87 1.98 1.10 15.40 19.63 6.68 20.74 18.78 0.07 0.05 0.03 0.25 0.18 0.15 0.30 0.34
I guess that’s a starting point.
Have you used darktable-chart with Wolf Faust IT8 “288 patches” targets yourself?
Since my chart is “ColorChecker” – and not a ‘photographic target’, looks like I’m going to have to change the first line of the file NOT to read “IT8.7/x”?
But what do I put in instead? I can modify the patch identifiers to follow Wolf’s format, add in XYZ but does darktable-chart needs the Statistics part? To your knowledge.
I’ve used IT8 targets with Argyll scanin/colprof tools to make ICC camera profiles, but I’ve not used the darktable facility. My target was a Wolf Faust target; the Rxxxxxx.txt file worked with Argyll scanin just fine out-of-the-box. Wait to see if a darktable dev or user responds…
Do you have a cc24?? or do you have a 288 patch card?? If 24 I have them and will post when I get home…also I think you need to shoot it in landscape with the white patch lower left…I will have to confirm but I don’t think DTchart handles rotations so the orientation has to match your cht file…
I have a CC24. Any Wolf Faust IT8 goes through perfectly.
I tried to edit my reference file accordingly but darktable-chart is very picky, it refuses my file :
I give up. I tried editing the file all I could to no avail.
I read somewhere to run the application from the command line to recover any error, to no avail again.
The following line returns nothing:
Working with jpg54 at darktable.fr, it came down to the “order” : all along, I was using X-Rite’s “traditionnal” Columns by Columns order while darktable-chart, in the “spirit” of argyll *.cht format, expected Rows by Rows order. Go figure! Once I changed the patch order, the sun started to shine again! Thanks so much for you kind help. FWIW, this is the correct data file :
