- From: Jon Sneyers via GitHub <sysbot+gh@w3.org>
- Date: Sun, 20 Apr 2025 09:13:39 +0000
- To: public-css-archive@w3.org
Relying on metadata provided by the creators themselves does not solve the issue since it is easy to just lie in the metadata. Computing the average light level might be a bit too computationally expensive to do on the fly in the browser, but something computationally cheaper could be done like counting the fraction of pixels with RGB values above the SDR max value (e.g. above signal value 0.58 in the case of PQ). Non-malicious HDR images might contain a somewhat larger amount of bright pixels, e.g. for outdoors photos at daytime, it may be desirable to have the sky brighter than SDR white, though probably most of it should still be kept at +1 stop above SDR white or so, not much brighter. To catch 'malicious' HDR images, maybe a good threshold would be +2 stops above SDR white (or the simpler equivalent of that in individual R,G,B values, e.g. above signal value 0.75 in the case of PQ — even if some of those could be just very saturated but not very bright). The fraction of pixels above +2 stops should be small in any 'reasonable' HDR image, say no more than 2%. This whole issue feels similar to the issue of audio loudness normalization. -- GitHub Notification of comment by jonsneyers Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/12096#issuecomment-2817078533 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Sunday, 20 April 2025 09:13:41 UTC