[argyllcms] [Script-based / fake] How to create my TI3 file?

  • From: tb <baruchel@xxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 25 Sep 2011 10:37:38 +0200 (CEST)


I am trying to use argyllcms for building a color profile. I have a camera
which outputs its undocummented proprietary RAW file with linear data.
I am happy with the standard sRGB (or AdobeRGB, ProPhotoRGB, etc.) color
pictures made by an undocummented proprietary workflow. I would like to
study the colorspace of my camera.

Now, I have two files for the same picture (not pictures of a chart; just
think to a picture of a dog, of flowers or whatever you want):
  - the RAW file with some linear "RGB" data (PIC1)
  - the corresponding sRGB (or whatever) TIFF data (PIC2)

I found a very interesting thread, which is not too far from what I
am trying to do:

But the thread was about picture of a chart. What I would like to do is
the following thing: with a script, I would like to extract pixels at the same
coordinates in both pictures and to have the following columns:

  column1: Red (unknown color profile) from PIC1
  column2: Green (unknown color profile) from PIC1
  column3: Blue (unknown color profile) from PIC1
  column4: "target" Red (sRGB or whatever known RGB) from PIC2
  column5: "target" Green (sRGB or whatever known RGB) from PIC2
  column6: "target" Blue (sRGB or whatever known RGB) from PIC2

and I would like my script to write a ti3 (or maybe a cgats data txt file
if it is more relevant) without having to care about color charts.

Later I will think more concerning the best strategy for selecting 100 or 500
or 1000 pixels (random pixels? selected pixels by some algorithm? etc.) But
right now, I want to select say 200 random pixels in PIC2 and call them
"target values" and see what are the data in PIC1 for these "target values".

But I am very new to this topic, and I couldn't find good examples
of TI3 files (or cgats data txt files) on the net. Of course, I could
find the following page: http://www.argyllcms.com/doc/ti3_format.html
But a short example would be much easier.

Could you show to me such a "basic", clean and simple TI3 file (or cgats
data txt file) for such a six-column-based set of data?

Best regards, T.

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