[css-color] DCI P3 transfer function

[svgeesus]

https://drafts.csswg.org/css-color/#predefined

DCI transfer function for P3 is gamma 1/2.6 while Apple P3 displays use gamma 1/2.2.

[svgeesus]

1/2.6 is appropriate for a totally black viewing environment. For the web, a 1/2.2 (or sRGB) transfer curve is more appropriate for typical viewing conditions.

Typically, the deciding factor is based on the general ambiance of the room. A darker room requires a higher power (the reason why cinema projections in a completely dark room use gamma 2.6). A good rule is to use a value around 2.0 for daylight uncontrolled lighting, 2.2 for dim lighting, 2.35-2.4 for a dark controlled room, and 2.5-2.6 for pitch black.
David Torciva
https://davidtorcivia.com/lets-talk-monitors-display-basics/

Since graphics cards have hardware support for the sRGB transfer curve (whose overall gamma is close to a 2.2 curve), I wonder if we can specify the DCI-P3 primaries and whitepoint and the sRGB transfer curve. Rec 2020 also uses an sRGB-like curve, with a linear portion near black, except with higher precision to cope with 10bit or 12bit per component displays.

[svgeesus]

Confirming that multiple devices with a P3 mode use 2.6 gamma. Samsung Galaxy S7 is one.
Dell UP2716d is another. Seems aimed at P3 video editing and thus darkened room.
https://pcmonitors.info/reviews/dell-up2716d/

[svgeesus]

Clarifying that image-p3, which is the same as Apple's Display P3, uses the same primary chromaticities as DCI-P3, but a different whitepoint (D65), transfer curve (same as sRGB) and viewing condition (same as sRGB?).

kCGColorSpaceDisplayP3

The name of the Display P3 color space, created by Apple Inc. This color space uses the DCI P3 primaries, a D65 white point, and the same gamma curve as the sRGB color space.
https://developer.apple.com/documentation/coregraphics/kcgcolorspacedisplayp3?language=objc

If content is actually using DCI P3, it can do so with an @color-profile rule.