Colour correction parameters

Anything and everything to do with DCP-o-matic.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Colour correction parameters

Post by Carsten »

That's how it looks when I start 1.78.8 under a new user on my Mac, this way now it should come up with default prefs?.
Bildschirmfoto 2015-05-05 um 00.16.29.png
Bildschirmfoto 2015-05-05 um 00.16.29.png (44.1 KiB) Viewed 7153 times
- Carsten
carl
Site Admin
Posts: 2338
Joined: Thu Nov 14, 2013 2:53 pm

Re: Colour correction parameters

Post by carl »

Ah, got it, thanks ... an i18n problem; Rec. 601 is fuzzily translated as Rec. 709 in de_DE. I've removed the preset config altogether now (locally). I think I'll try that and see if anybody notices. I doubt anyone is using the capability to edit / add new preset.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Colour correction parameters

Post by Carsten »

Hmm, it would be good to have that ability, just how prominent, that is the question. One issue now certainly is the transition from the old conversion prefs to the new system, so people may end up with a weird set of converted conversion presets. What about having 4-5 'fixed' conversions (sRGB, rec.709, P3, etc) which can not be edited, and then offer additional individual presets? It's certainly important that users can always fall back to a well defined set of conversion parameters.


BTW - it seems that the Mac version, when started without prior existing prefs, uses a strange mixture of german and english language for the GUI. That is with the 'set language' check mark unset. Very strange.
When setting either language manually, it comes up properly.

- Carsten
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Colour correction parameters

Post by Carsten »

Hmm, when I do a fresh install in windows, it shows up the same as above - and I'm perfectly okay with these 4 default presets. There is one for sRGB, one for Rec. 709 with the Rec.709 YUV matrix for HD, one REC. 709 with the CCIR601 YUV matrix for SD, and the new P3 preset.


I just think the two 'REC. 709' should get different names so people can tell the difference. As I wrote above, I think SD and HD as designators is as clear as possible. Using 'CCIR601' and another 'REC. 709' would be too confusing.

And then maybe fix these four and make them not editable, but allow others to be created. And copy from one of the 4 existing as the source for a new preset. The color transformation matrix may be too exotic indeed to be actually used by people. But input/output gamma could indeed be very useful and is more easy to use if needed.

I'm wondering how other DCP creation tools deal with this...

- Carsten
RaquelGomez
Posts: 8
Joined: Tue Apr 12, 2022 4:14 pm

Re: Colour correction parameters

Post by RaquelGomez »

Hello,
I am new here, trying to see how to make it right. I am reading all the posts related. But in my DOM 2.14.48 git 9131cb3870 cannot see the preference's color settings (as you showed in the pic). I did export my file with Premiere 2020 as Apple Prores 4:2:2 HQ, Rec709 16bit -stereo PCM 24bit single file. I understand DOM does the translation from Rec709 to the space of ZYX and from 2.2 gamma to 2.6. But how can I verify this has been done. On my first dcp try's I did not see the characteristically greenish image of applying the ZYX when playing the dcp on DCP-o-matic 2 player, with a regular monitor. (Beng PD Series). I have also imported files again to Resolve on a new project and I see it like always (I believe I shouldn't).

On my settings inside the DOM project I did say my source video was rec 709 (s. Attachment)
Captura de pantalla 2022-04-19 a las 18.28.13.png
Captura de pantalla 2022-04-19 a las 18.28.13.png (8.21 KiB) Viewed 802 times
The questions are:
Is there a way to see if it is ok in the file, by media info and/or by visual methods?
I am using the settings correctly? Should I look somewhere else?

Thank you in advance.
Carsten
Posts: 2648
Joined: Tue Apr 15, 2014 9:11 pm
Location: Germany

Re: Colour correction parameters

Post by Carsten »

You will only see the greenish tint with a player that does not perform the reverse X'Y'Z'->sRGB conversion. DCP-o-matic player will not show greenish images because it will always perform the proper display conversion.

I you exported you file in rec.709 from Premiere, DOMs default color conversion will be right.
RaquelGomez
Posts: 8
Joined: Tue Apr 12, 2022 4:14 pm

Re: Colour correction parameters

Post by RaquelGomez »

Great, So it seems it has to be ok. Thanks for your fast reply Carsten.
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