W3C home > Mailing lists > Public > www-style@w3.org > November 2015

Re: [css-color] wider/deeper colors

From: Florian Rivoal <florian@rivoal.net>
Date: Wed, 4 Nov 2015 10:05:54 +0900
Cc: www-style <www-style@w3.org>, Chris Lilley <chris@w3.org>
Message-Id: <A0DC722C-0B51-4054-A04F-6FDE549EB4A6@rivoal.net>
To: Dean Jackson <dino@apple.com>

> On 04 Nov 2015, at 09:27, Dean Jackson <dino@apple.com> wrote:
> 
> 
>> On Nov 2, 2015, at 5:16 PM, Dean Jackson <dino@apple.com> wrote:
>> 
>>> 
>>> On Nov 2, 2015, at 4:57 PM, Florian Rivoal <florian@rivoal.net> wrote:
>>> 
>>> 
>>>> On 03 Nov 2015, at 08:09, Dean Jackson <dino@apple.com> wrote:
>>>> 
>>>> Hi,
>>>> 
>>>> We had a productive discussion about colors outside sRGB last week and I wanted to summarize the outcome. I also have provided some new comments. Please let me know if I got details incorrect. And please remember, IANACE (color expert).
>>>> 
>>>> 1. Add a new media query that is able to detect the "depth" of the display. I put that word in quotes because I think the current "color" query isn't sufficient and we need a term to better describe what we're trying to detect. The "color" query examines the number of bits per channel, but that doesn't allow you to ask if the display can show things outside sRGB. Instead we suggest there should be range-type query that allows you to detect "normal" (typical displays from today, in the sRGB range or about), "extended" (wider gamut displays, in the DCI P3 range or about) and "super-awesome-needs-a-better-name" displays (very wide gamut displays, in the Rec. 2020 range or about). I believe this might be the first media query that has named values but works as a range. We don't have good suggestions for the name of this query.
>>> 
>>> Note sure this has to be a range query. If you go with "awesome-colors: none | some | plenty", you can do "@media (awesome-colors) {...}" and have it match whenever the value is something other than none. Wouldn't that be enough?
>> 
>> Yeah, that should work. We just need to think of names.
> 
> We're not so sure about this any more. You might get horrible results if you authored for "plenty" and got "some" - you certainly do if you author for "some" and get "none".
> 
> You really want to build it up the other way around, and thus a min/max approach works best.
> 

I'm not sure.

If you author for plenty, you should query for (awesome-colors: plenty).

I'm assuming that the use case for querying for (awesome-colors) is that you don't want to throw anything but sRGB at the screen so long as awesome-colors is none, but if you get anything else, you can expect that not only is the screen capable of displaying a wider gamut, but the software stack is also aware of it, and should be able to handle gracefully wide gamut images, even if they exceed the screens gamut ("gracefully" probably depends on rendering intent).

In that sense:
 - (awesome-colors:none) means "use sRGB or else!"
 - (awesome-colors) means it's fine to use anything
 - (awesome-colors:plenty) means can you use anything, and that it's going to be gorgeous if you do use wide-gamut.

Which makes me think that maybe we should change the semantics of the 3 values to be actually that
- one of the values means no color management, sRGB assumed everywhere
- the second value means color management is available and non sRGB color will be handled smartly, but there is no particular promise of super wide gamut output medium
- the third value means color management is available, and the output medium's gamut is meaningfully larger than sRGB.

/Florian
Received on Wednesday, 4 November 2015 01:06:27 UTC

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