Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?

I haven’t made contact with Pixelmator folks yet. But here are the Affinity Folks.

I’m corresponding with:

Andy Somerfield asomerfield@serif.com<mailto:asomerfield@serif.com> (dev)
John Atkin john@serif.com<mailto:john@serif.com> (PR)

This is what Andy shared so far:

Internally, Photo manipulates HDR content as ICC profiled, linear 32bit floating point data. Conversion from PQ / HLG is dealt with at import time (for example, a PQ encoded HEIF from a Canon camera will be converted to Linear sRGB).

All compositing is then done in a linear colour space and we support a number of clipping visualisation options as well as native HDR display (which is presently a bit better on Mac than Windows - Apple’s approach to HDR display is the right approach, but others are yet to properly copy it). A large number of (nearly all) Photo features work properly in 32bit HDR - aside from the obvious (Invert, etc. where there is no logical “Maximum”).

We currently do not support encoding to PQ / HLG at export time - although it’s something we are actively looking to do. I guess we are waiting for the format war to conclude (or rather, to begin..)

Our 32bit compositing pipeline was developed primarily for VFX users - so our EXR round-trip stuff is pretty good - but that’s not what you’re looking for, I assume.

-Chris


From: Chris Blume (ProgramMax) <programmax@gmail.com>
Date: Wednesday, December 6, 2023 at 1:45 PM
To: Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com>
Cc: Portable Network Graphics (PNG) Working Group <public-png@w3.org>
Subject: Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?
Do we have contacts at either of those two companies?

On Wed, Dec 6, 2023 at 12:39 PM Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com<mailto:Chris.Seeger@nbcuni.com>> wrote:
Thanks so much 😊. This will move us forward more quickly.

Two new apps to test that might be worth some more investigation:

Photomator
https://apps.apple.com/us/app/photomator-photo-editor/id1444636541<https://urldefense.com/v3/__https:/apps.apple.com/us/app/photomator-photo-editor/id1444636541__;!!PIZeeW5wscynRQ!p_ez9avjNcZUjumErOtECBA-lsR2cn4LVb2Y1Z2g_SZ18aSceD1onLjF28JZsu_85wsz__0QELd90TshvzdG$>

Affinity Photo
https://apps.apple.com/us/app/affinity-photo-2/id1616822987?mt=12<https://urldefense.com/v3/__https:/apps.apple.com/us/app/affinity-photo-2/id1616822987?mt=12__;!!PIZeeW5wscynRQ!p_ez9avjNcZUjumErOtECBA-lsR2cn4LVb2Y1Z2g_SZ18aSceD1onLjF28JZsu_85wsz__0QELd90REW-68w$>


Best,
Chris

From: Chris Blume (ProgramMax) <programmax@gmail.com<mailto:programmax@gmail.com>>
Date: Wednesday, December 6, 2023 at 11:52 AM
To: Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com<mailto:Chris.Seeger@nbcuni.com>>
Cc: Portable Network Graphics (PNG) Working Group <public-png@w3.org<mailto:public-png@w3.org>>
Subject: Re: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?
Simon is right.
I'll work on adding cICP chunks now.

On Wed, Dec 6, 2023 at 11:11 AM Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com<mailto:Chris.Seeger@nbcuni.com>> wrote:
Yes.  They are public. Can we start with cicp only as they are not required for PQ, HLG or SDR?

If you show me how to do it, and with what tools, maybe I can help.

Best,
Chris

Get Outlook for iOS<https://urldefense.com/v3/__https:/aka.ms/o0ukef__;!!PIZeeW5wscynRQ!uLCseTAx_Hyxx7ImY4JuTY9ZQE6yQqk9WuV4Jp7w5pOovkCOED_tSs63dlwwyry1KgwghWlvJWWUJ5s7UYwx$>
________________________________
From: Chris Blume (ProgramMax) <programmax@gmail.com<mailto:programmax@gmail.com>>
Sent: Wednesday, December 6, 2023 10:37:11 AM
To: Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com<mailto:Chris.Seeger@nbcuni.com>>
Cc: Portable Network Graphics (PNG) Working Group <public-png@w3.org<mailto:public-png@w3.org>>
Subject: [EXTERNAL] Re: Conformance files in PQ, HLG, SDR-BT.709?

I can hexedit in cICP values.

Although, maybe I should wait until we have mDCv and cLLi values as well? How long do you think it would take to get those values?

My thought is: I don't want to start distributing test images only to later tell people to use these new test images instead (when they don't yet have a way to see which ones are new/old).
But maybe it will take a while to get mDCv and cLLi values. So maybe it would be good to get some new test images sooner?

(Are these images public domain? Can we distribute them widely?)

On Wed, Dec 6, 2023 at 8:53 AM Seeger, Chris (NBCUniversal) <Chris.Seeger@nbcuni.com<mailto:Chris.Seeger@nbcuni.com>> wrote:

Hi Chris and All,



Do we have any conformance files in each format (PQ, HLG, SDR-BT.709)? I’ve got a number of developers who’d like to add the functionality into their apps. Once of them requested test files.



I’ve created test files if someone can add cICp chunks to them:



https://www.dropbox.com/scl/fo/a44vfxw3p21kvkh8nywpc/h?rlkey=v63ekq5y49kd4omg59ng9q3zr&dl=0<https://urldefense.com/v3/__https:/www.dropbox.com/scl/fo/a44vfxw3p21kvkh8nywpc/h?rlkey=v63ekq5y49kd4omg59ng9q3zr&dl=0__;!!PIZeeW5wscynRQ!u3P4S_qNlSUgxiBGGql3lAci2mnjiYXwiMFO_BJmTverJdmVa01jIZup7LNb0VmqqIefc7ZiC_qDHR576Lqb$>



SDR CICP: 1-1-1 (Narrow and Full Range versions marked NR or FR)

PQ CICP: 9-16-9 (Full Range only as there is no benefit to NR PQ)

HLG CICP: 9-18-9 (Narrow and Full Range versions marked NR or FR)



I will send mDCv and cLLI values (just an example at a later date since cICp is most important to get to developers).



Thanks very much,



Chris Seeger

Director, Advanced Content Production

Office of the CTO

C: 551-238-3768

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