- From: Andrew Somers via GitHub <sysbot+gh@w3.org>
- Date: Tue, 12 Oct 2021 15:44:56 +0000
- To: public-css-archive@w3.org
Hi Chris @svgeesus > ..._In practice this means that most RGB to RGB conversions will proceed via CIE XYZ with a D65 whitepoint_. ... YAY! Seriously, as you know I agree, I applaud this move and I do recognize the difficulty of changing course on issues like these. With the rapid moving toward a more HDR/WGC world, IMO _**realtime gamut mapping**_ is going to become the new _"we gotta urgently fix the performance"_ and one part of that is a common whitepoint. > _Most RGB colorspaces use a D65 whitepoint. (The sole exception in CSS Color 4 is ProPhoto RGB D50 ... DCI-P3.... has a weird greenish white, and ACEScc ....). ..... most RGB to RGB conversions will proceed via CIE XYZ with a D65 whitepoint._ I remember making some comments about ProPhoto when it was added a couple years ago, and I still don't quite get why a non-display space that's mainly for physical print workflow is part of the web which I've always seen as a delivery/distribution space (even if dynamic content is assembled on demand)... The reason ProPhoto is useful is for adjusting in RGB material destined for CMYK... but IMO ProPhoto is a poor choice if the destination is an RGB-display type space, for more reasons than I'll bore everyone with. **This makes me wonder, there must be envisioned use cases I am not aware of....?** DCI P3 is a little odd, it's a weird WP due to projector mfgs wanting to have max output from a xenon bulb, so basically that defines the WP and it's not exactly constant... Before DCI, SMPTE 196M defined the white point for a movie theatre as 5400°K +600° -200°. This gives a range from 5200° to 6000°, But naturally the real world variation was: <img width="707" alt="Screen Shot 2021-10-12 at 8 23 05 AM" src="https://user-images.githubusercontent.com/42009457/136984738-0fe4431d-cf54-44f3-87c3-a4e21d69ef65.png"> ...speaking of hand wavy hand waving.... So DCI P3 was basically set at "xenon native" ... ACES is a similar story, but it's more based on the working group doing a series of tests and comparisons and an unknown amount of wavy-ness to set the WP far enough off the planckian locus that you could use it for dart board practice. That probably doesn't make sense but its the analogy that popped into my head., LOL. ## _Do I actually have a point this morning?_ My point is really that DCI and ACES are part of a tightly closed ecosystem, and having to do with xenon projectors. In *our* ecosystem of distributing little ones and zeros world wide to anyone that asks, it's just D65 and I'm thinking the likely progression is going to be something like: - We're on sRGB now, - Display P3 D65 is next, because it uses ready to go tech and give manufacturers hope that people are going to buy new displays to replace their otherwise perfectly good sRGB and Adobe98 displays... - Then, in a few years, Rec2020/2100... but I think the MFGs will want to unload as many P3 monitors as they can, and not sell Rec2020/2100 ones for a while... then, after everyone has P3s, they can push the Rec2100s to sell more monitors to replace perfectly good P3 monitors... And then what? Laser primaries right on the spectral locus and HDR, what is anyone going to need to "trade up to" after that? ...Brain implants I suppose. -- GitHub Notification of comment by Myndex Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6722#issuecomment-941135876 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 12 October 2021 15:44:58 UTC