- From: Andrew Somers via GitHub <sysbot+gh@w3.org>
- Date: Tue, 02 Mar 2021 19:46:46 +0000
- To: public-css-archive@w3.org
Hey Chris @svgeesus > _but it is not clear that the cube-root L power law is appropriate above media white._ I have been exploring a lot of this lately as I really would like to understand why "middle contrast" is not at all the same as the accepted "middle grey" ... cube root is increasingly less accurate above 100, and is also less accurate in the mesopic range — under 4.0Y in particular actual sensitivity seems closer to log. I am presently, increasingly of the opinion that "`L*` is not super useful for self illuminated displays." And for HDR I think I am safe to say that `L*` is nearly meaningless. For sRGB, I have been working on some alternatives: **L<sup>s</sup>** and one possible definition is: ### L<sup>s</sup> = Y<sup>0.62</sup> * 121 - 21 _(this does not include the needed adjustment at very dark values to compensate for the offset)_ The actual exponent is somewhere between 0.55 and 0.62, and obv. affected by the ambient/light adaptation, and making some assumptions such as _"middle contrast should be the same as middle grey"_ and I am not 100% sold on any of this, it's all very much in-progress stuff. BUT If you want to play around with some of the experiments, there's a "research mode" at the SAPC dev site, and you might find the "middle contrast" experiment interesting. https://www.myndex.com/SAPC/ -- GitHub Notification of comment by Myndex Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6061#issuecomment-789167421 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Tuesday, 2 March 2021 19:46:48 UTC