15 Oct
2014
15 Oct
'14
11:01 a.m.
Here's a question for the list! :) Any suggestions, anyone?
---------- Forwarded message ----------
Date: Tue, 14 Oct 2014 16:16:10 +0100
From: Anand Madabushi <armadabushi(a)gmail.com>
To: carl(a)dcpomatic.com
Subject: P3 to XYZ conversion matrix
Hi Carl,
I've got a feature film that's currently sitting in DCI-P3 colour space. I'd
like to use a custom matrix to convert this space to XYZ using your awesome software.
You currently have 3 presets, but not a P3 one. I've scoured the web trying to find a
3x3 matrix to do this conversion and even tried to calculate one
mathematically - with no success. I would assume others have tried to do something
similar.
Any idea where I can find a conversion matrix for P3 to XYZ?
Many thanks,
Anand Madabushi
Outsight Films, London
15 Oct
15 Oct
11:30 a.m.
You currently have 3 presets, but not a P3 one.
I've scoured the web trying to find a 3x3 matrix to do this conversion and even tried
to calculate one
mathematically - with no success. I would assume others have tried to do something
similar.
Any idea where I can find a conversion matrix for P3 to XYZ?
The closest I could get:
http://www.mjbcolor.com/Digital_Projector_Standards_Setup.html
This guy also has an amazing amount of documents on his site dealing with colour science
and conversions. He sure would know how to do P3 to xyz, but I don't know wether he
would answer that question for free. ;-)
What software did you use to create the P3 file?
As a matter of fact, I always thought that P3 and xyz were more or less identical, as both
are referenced as DCI colour space. I thought P3 was only a link-method to transmit xyz
over HD-SDI.
- Carsten
1:03 p.m.
Maybe this helps in creating a matrix:
DCI-P3
Gamma 2.6
White point
x 0.314
y 0.351
Red
x 0.680
y 0.320
Green
x 0.265
y 0.690
Blue
x 0.150
y 0.060
From what I understand now, xyz is the storage format within the DCP, while P3 is the
color space used by DCI projector itself. When a server plays a DCP, it transmits xyz to
the projector. The projector will convert to and show P3.
In a grading situation with a projector connected directly to the grading workstation for
realtime playout, the xyz conversion is omited and P3 is played directly from the grading
workstation into the projector. A DCI projector therefore needs at least two different
input profiles - P3 1:1, or xyz->P3.
Now if you say you have a file sitting in P3 color space - what does that mean? Is it the
color space associated with the editing project, or do you have a file rendered out in P3
- if so, which container/codec?
- Carsten
3848
days inactive
3848
days old
2 comments
2 participants
participants (2)
-
Carl Hetherington -
Carsten Kurz