- From: Chris Lilley via GitHub <sysbot+gh@w3.org>
- Date: Wed, 10 Mar 2021 23:03:34 +0000
- To: public-css-archive@w3.org
> the first color equivalency experiments with human subjects in the 20s and 30s were using mixing with negative percentages and the subjects seemed to be having no trouble with the concept. I will try to find a source to cite. >> Notice that a considerable portion of the red curve in the shorter wavelength portion of the spectrum lies below the axis; _that is, its values are negative!_ This feature is an expression of the fact that light of these wavelengths could not be matched by any mixture of the primaries. However, when the red primary was shifted to mix with the unknown rather than the other primaries (i.e. ‘negative’ light), a match could be obtained. >> Since it was thought to be inconvenient to deal with colour matching functions containing negative values, a linear transformation was used to convert the rgb curves to x-bar, y-bar, z-bar curves having no negative values. https://www.sciencedirect.com/topics/engineering/color-matching-function -- GitHub Notification of comment by svgeesus Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/6047#issuecomment-796267733 using your GitHub account -- Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config
Received on Wednesday, 10 March 2021 23:03:36 UTC