Re: [csswg-drafts] [compositing] SDR and HDR compositing

Also, if my understanding is correct (and it very well may not be), 
the problem with that is that HDR luminance is an absolute scale, 
while SDR is a relative one (relative to a white diffuser). If we map 
SDR to HDR, it means we absolutize the luminance range of SDR, which 
leaves us with the question of what to do when the user/OS wants to 
adjust the screen brightness, or similarly, how to display the SDR 
range on screens whose peak brightness is less than the one we picked 
as the absolute luminance of the white diffuser. Also, this would 
prevent us from boosting the luminance of SDR content to view it in a 
bright environment.

The alternative of making the HDR luminance scale relative to the 
white diffuser, and therefore no longer having an absolute luminance, 
seems to have fewer practical downsides, even if it is theoretically 
just as wrong.

Or maybe we just let HDR fall where it should, and say that the 
luminance of the SDR white diffuser should be `min(peak screen 
brightness at current settings, 300nt)`

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Received on Friday, 30 September 2016 01:45:58 UTC