Re: [EXTERNAL] Re: Proposal for HTMLCanvasElement HDR compositing modes

We agree.  Please stay in Display-Light.

From: Jim Helman <jhelman@movielabs.com>
Date: Monday, March 15, 2021 at 11:54 PM
To: Lars Borg <borg@a1830.dscd.akamai.net>, Christopher Cameron <ccameron@google.com>, public-colorweb@w3.org <public-colorweb@w3.org>, Pierre-Anthony Lemieux <pal@sandflow.com>
Subject: [EXTERNAL] Re: Proposal for HTMLCanvasElement HDR compositing modes

Hi,

I agree. Scene light has a very specific definition in the context of capture and in the color grading/correction world. In our context here, we should avoid getting into mappings from scene-referred to display-referred systems, which are usually highly subjective and depend on the desired creative "look."

- Jim
On 3/15/21 8:26 PM, Lars Borg wrote:
Chris C,

One concern I have is the term scene light.
If this means scene-referred, then that’s a problem as sRGB is defined only for display light, not for scene light.
So then additional conversions would be needed to convert sRGB to canvas.
And if scene light doesn’t mean scene-referred then what does it mean? It causes confusion.
Please find a way to stay in display-referred color space.

Lars

From: Christopher Cameron <ccameron@google.com><mailto:ccameron@google.com>
Date: Sunday, March 14, 2021 at 8:30 PM
To: "public-colorweb@w3.org"<mailto:public-colorweb@w3.org> <public-colorweb@w3.org><mailto:public-colorweb@w3.org>, Pierre Lemieux <pal@sandflow.com><mailto:pal@sandflow.com>
Subject: Re: Proposal for HTMLCanvasElement HDR compositing modes
Resent-From: <public-colorweb@w3.org><mailto:public-colorweb@w3.org>
Resent-Date: Sunday, March 14, 2021 at 8:29 PM

FYI, I have updated the PR to rely more heavily on standard broadcast terminology, and included a (hopefully-clarifying) definitions section at the top.


On Wed, Mar 10, 2021 at 2:42 PM Christopher Cameron <ccameron@google.com<mailto:ccameron@google.com>> wrote:
I put up a PR with a writeup of what I think is the best scheme for HDR compositing of HTMLCanvasElements, given our various constraints. Please review and/or comment for our next meeting on March 16!
https://github.com/w3c/ColorWeb-CG/pull/15<https://urldefense.com/v3/__https:/nam04.safelinks.protection.outlook.com/?url=https*3A*2F*2Fgithub.com*2Fw3c*2FColorWeb-CG*2Fpull*2F15&data=04*7C01*7Cborg*40adobe.com*7Cf4f9872e7f6a408760f808d8e77bbfcf*7Cfa7b1b5a7b34438794aed2c178decee1*7C0*7C0*7C637513866045481738*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C1000&sdata=vAN*2BA6ZzmQ4r*2F3m7SlyZVOU4s8nn5nu50rjT0S2XpfU*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJQ!!PIZeeW5wscynRQ!6mlLIp7Z_m5FoUU-qfpGA4Tn3i4RMsTXJuy0E55neWP9Vv8L36ITozr3pAZp6rofTA$>

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Jim Helman | MovieLabs | o: +1.650.646.2277 m: +1.650.576.1755 | jhelman@movielabs.com<mailto:jhelman@movielabs.com> | 222 Kearney St, Suite 300, San Francisco, CA 94108