[css-color-hdr] auto value of dynamic-range-limit · Issue #11558 · w3c/csswg-drafts (original) (raw)

A new value is needed to allow the user agent to dynamically change the brightness of the HDR video, image or canvas based on the page/screen content or the system conditions.

In WebKit, we're still discussing exactly when to allow various HDR limits, but it's clear that the used HDR limit will be a result of various factors, including user choice, system state (e.g. low power mode), and system policies around when full HDR is appropriate. To this end, we believe that we need an auto value, which should be the initial value. Generally we'll allow auto to result in constrained-high, with high in some specific circumstances like video fullscreen.