XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Anything and everything to do with DCP-o-matic.
Wojtas
Posts: 2
Joined: Wed Jul 30, 2025 2:02 am
Location: Poland

XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by Wojtas »

Hi everyone,
I'm experiencing a problem with the recent versions of DCP-o-matic.

I have a large archive of films stored as DCDM files, in XYZ color space with gamma 2.6. I’ve been creating DCPs from TIFF sequences using DCP-o-matic, selecting "None" in the color conversion settings to avoid any color transformation.

Up to version 2.18.18, everything worked perfectly - DCP-o-matic handled it very well.

However, since version 2.18.19, even with the "Color: None" option selected, it seems like some transformation is still being applied. In the Player, the image still looks like it's in XYZ- the color appears incorrect.

Has anyone experienced something similar?
Is it possible that something has changed in how input is processed since that version?
Thanks in advance for any help or suggestions.
Carsten
Posts: 3010
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by Carsten »

There was indeed a recent change to the 'none' color transformation option. However, that was meant to actually solve a problem, not to create one...

https://dcpomatic.com/forum/viewtopic.php?t=2735

https://dcpomatic.com/mantis/view.php?id=3066

Can you try an older version to see wether it makes a difference for you?
carl
Site Admin
Posts: 2852
Joined: Thu Nov 14, 2013 2:53 pm

Re: XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by carl »

Hi, yes I think I broke one case in trying to fix another. I will upload a test version for you to try shortly!
carl
Site Admin
Posts: 2852
Joined: Thu Nov 14, 2013 2:53 pm

Re: XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by carl »

It would be great if you could try this build and see if it works any better:

https://dcpomatic.com/build/3066-colour/e0422e2
Wojtas
Posts: 2
Joined: Wed Jul 30, 2025 2:02 am
Location: Poland

Re: XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by Wojtas »

Everything’s working perfectly now!
Huge thanks, Carl I absolutely love your app and really appreciate all the work you’re putting into it.
TonyK
Posts: 13
Joined: Wed Sep 17, 2025 2:03 pm

Re: XYZ to DCP color handling changed in DCP-o-matic 2.18.19?

Post by TonyK »

Hi so I have tested the version 877dd7904 and unfortunately the green XYZ that on my monitor is the same on the dcp ? After installing the build, I opened up the project. Don’t think this is why there’s no change in the outcome