- From: Alan Gresley <alan@css-class.com>
- Date: Tue, 15 Oct 2013 09:25:12 +1100
- To: Chris Lilley <chris@w3.org>, Rik Cabanier <cabanier@gmail.com>
- CC: Michael Mullany <michael@sencha.com>, "public-fx@w3.org" <public-fx@w3.org>
On 15/10/2013 7:23 AM, Chris Lilley wrote: > Hello Rik, > > Incidentally these polar forms were what inspired Tektronix et al to > come up with HSL, HSV and similar polar forms of RGB. Unlike the > measurement-based CIE forms, however, HSL and HSV are not perceptually > uniform and have some odd behaviour - primary blue (#00F) and secondary > yellow (#FF0) have the same lightness in HSL and the same value in > HSV. Why do you say they are not perceptually uniform and have some odd behaviour? From my understanding, both primary blue (#00F) and secondary yellow (#FF0) are complementary to each other [1] but in gray-scale, secondary yellow is much lighter than primary blue [2] since it appears much higher in a sRBG cube (X,Y,Z axes) and more so if we consider that the sRBG cube has an orientation that is tilted on each axes (X,Y,Z) when considering overall gray-scale of lightness from white to black [3]. There is nothing odd about colour in this respect. >> However, doing so would require a whole new set of formulas in the >> filters specification and a lot of work in the browsers... > > Not really. In each case, you transform to the working colourspace, > perform channelwise operations, then transform back. 1. http://css-class.com/articles/color/index.htm#yellow-blue 2. http://css-class.com/test/css/colors/hsl-in-sRGB-color-space.htm 3. http://css-class.com/test/css/colors/color-cube-grayscale.htm -- Alan Gresley http://css-3d.org/ http://css-class.com/
Received on Monday, 14 October 2013 22:25:42 UTC