Design Review #1027

#1027: CSS `dynamic-range-limit`

Opened Dec 10, 2024

こんにちは TAG-さん!

I'm requesting a TAG review of CSS dynamic-range-limit

The goal of this proposal is to provide a mechansim through which an application may limit the maximum brightness of HDR content (including images, videos, and in the future HTML canvases and CSS colors).

Explainer¹: https://github.com/ccameron-chromium/hdr-headroom-limit/blob/main/EXPLAINER.md
Specification: https://drafts.csswg.org/css-color-hdr/#controlling-dynamic-range
WPT Tests: https://wpt.fyi/results/css/css-color-hdr?label=experimental&label=master&aligned
User research:
Security and Privacy self-review²:
GitHub repo:
Primary contacts:
- @ccameron-chromium, Google, proposal author, Chromium author
- sboukortt, Google, Chromium implementor
- @svgeesus Editor of CSS Color HDR spec
Organization/project driving the specification:
Multi-stakeholder support³:
- Chromium comments: Positive
- Mozilla comments: https://github.com/mozilla/standards-positions/issues/979
- WebKit comments: https://github.com/WebKit/standards-positions/issues/312
- Adobe requested support
Status/issue trackers for implementations⁴:
- https://chromestatus.com/feature/5146250411769856, https://crbug.com/40277822

Further details:

I have reviewed the TAG's Web Platform Design Principles
Relevant time constraints or deadlines: Aiming for Chrome 133 (early January)
The group where the work on this specification is currently being done: CSS WG
The group where standardization of this work is intended to be done (if different from the current group):
Major unresolved issues with or opposition to this specification:
This work is being funded by:

Discussions

Comment by @svgeesus Dec 10, 2024 (See Github)

Security and Privacy self-review²:

The spec has a Privacy Considerations which has the same description as the explainer on why we do not expose numerical headroom values, just three buckets.

The Security Considerations says that no security issues have been raised and there is also an Accessibility Considerations which explains the accessibility benefit of limiting the dynamic range.

Comment by @svgeesus Dec 18, 2024 (See Github)

The specification is now published to /TR

Discussed Feb 1, 2025 (See Github)

Dan: assigns Xiaocheng noting that Chris has noted the presence of a privacy consideration sand security considerations section... as well as an a11y considerations.

Dan: we can revisit at the plenary

Matthew: I will review as well.

Discussed Feb 1, 2025 (See Github)

Xiaocheng: we discussed last week.. the points are (1) we don't have anyone familiar with HDR so we should ask someone to take a look. Also a debate concerning the initial value.

Martin: the initial value looks fine to me...

we agree to hold off for now

xiaocheng to send a brief note about us waiting for an update

Comment by @xiaochengh Feb 19, 2025 (See Github)

Hi @ccameron-chromium, the TAG discussed it in a breakout today and noticed that there are some still open issues regarding the initial value of the property https://github.com/w3c/csswg-drafts/issues/11429 and https://github.com/w3c/csswg-drafts/issues/11558. We'll revisit it when the issues are resolved.