- From: bottosson via GitHub <sysbot+gh@w3.org>
- Date: Mon, 18 Oct 2021 17:05:32 +0000
- To: public-css-archive@w3.org
> The a and b plane is scaled so that around 50% gray the ratio of color differences along the lightness axis and the a and b plane is the same as the ratio for color differences predicted by CIEDE2000 To be clear, this statement captures my intent, but I think it isn't quite how Oklab as published ended up being. I've only recently realized this as I started to look more closely at color distance predictions. > scaling based on some dataset of color pairs will depend on the distribution of mean chroma in that data set This is in particularly true for small color distance datasets such as Combvd. For large scale distances this is less true, since there is less of a chroma compression effect. More visually: Small scale color distances show very strong elongation of spheres into ellipses:  OSA-UCS dataset models larger color distances and has much less chroma compression.  (It is also possible to much closer match the small color difference dataset as well, by introducing chroma compression, similar to what both CIEDE2000 and Ciecam02/16-UCS do, but that also adds quite a bit of complexity and assumptions on viewing conditions, this performs worse for tasks such as color interpolation) -- GitHub Notification of comment by bottosson Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6642#issuecomment-945980306 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Monday, 18 October 2021 17:05:34 UTC