3 ms·

Concepts of “whiteness” and “blackness” are fine, but this “HWB” is just a trivial rearrangement of RGB, and as such has very little to do with human perception

Concepts of “whiteness” and “blackness” are fine, but this “HWB” is just a trivial rearrangement of RGB, and as such has very little to do with human perception, and much more to do with the specific implementation details of the output medium. HWB (like RGB and HSL and HSV) does not make sense to “average human beings”. It only makes sense to people who have spent years training on the specifics of RGB displays (e.g. your proposed “lighting technicians”). For everyone else it is a confusing mess which produces bad results which differ significantly from their intentions. If you want a color model related to NCS, specify something which properly follows its principles. https://en.wikipedia.org/wiki/Natural_Color_System https://en.wikipedia.org/wiki/Natural_Color_System > magical shortcut This is neither magical nor a shortcut. It’s a superfluous hassle that anyone who wants to implement the spec needs to implement, debug, and maintain, and anyone reading the markup for arbitrary web pages needs to know about one more weird complication. If individual web designers want to use this idiosyncratic tool, they are welcome to put it in their page’s javascript, or add it to their CSS pre-processor. But it should not be foisted on the rest of us.

floatingatoll 7y ago
The NCS image at the link you provide above literally shows the exact three-cornered orange-white-black triangle at position -Y10R that is shown in this image, which appears to use the exact hue sequence shown in your wiki link’s animation. I’m confused why you object to it being supported. Is your objection to their use of Hue spectrum positions 0,90,180,270 (R,G,C,M) - as already implemented in CSS today - as the four saturated qualia rather than NCS’s specified four qualia positions of 0,90,180,270 (R,Y,G,B)? HWB: https://commons.wikimedia.org/wiki/File:GTK_color_chooser.png https://commons.wikimedia.org/wiki/File:GTK_color_chooser.pn... NCS: https://commons.wikimedia.org/wiki/File:Animation_of_the_NCS_Colour_System.gif https://commons.wikimedia.org/wiki/File:Animation_of_the_NCS...
- jacobolus 7y ago
  It is emphatically not “literally the exact [...] triangle”. The NCS is a similar concept, but executed based on a plausible theoretical model and (more or less) sound empirical study of human perceptual response to visual stimuli. “HWB”, like HSL, is just someone’s trivial half-assed transformation of the RGB cube, completely ignoring more than a century of color science research. It’s what you get when a person off the street were tasked with redefining the NCS, without understanding it. It reminds me of people’s bicycle sketches, http://www.gianlucagimini.it/prototypes/velocipedia.html http://www.gianlucagimini.it/prototypes/velocipedia.html Personally I am not the biggest fan of the NCS system for designating colors; I find Munsell-like coordinate systems to work better for me, in practice. But at least it has some kind of theoretical and empirical basis.
  - floatingatoll 7y ago
    This paper from a few years ago compares various mathematical definitions of "hue" that have been popular over the past few decades. https://pdfs.semanticscholar.org/7833/f96c09a1201f0e7f54e0de662e4faef36276.pdf https://pdfs.semanticscholar.org/7833/f96c09a1201f0e7f54e0de... CSS, having already standardized on Munsell hue circles (page 5) in the past, appears content to continue forward with them as the hue circle of choice for HWB. While I respect that you would prefer to see them use the NSL hue circle (pages 10-11), it appears that they are unlikely to do so at this time. One bonus find here is the abstract for the cited Whitfield (1988) paper, where the paper's authors attempted to replicate the assertion that NSL is better than Munsell, and failed: https://onlinelibrary.wiley.com/doi/10.1002/col.5080130210 https://onlinelibrary.wiley.com/doi/10.1002/col.5080130210 The study reported here is a replication of experiments cited as support for this claim. Subjects were trained in the NCS using NCS training material and carried out colour‐identification tasks. For comparison, a further subject group was trained in the Munsell system and carried out identical tasks. The results indicated (a) a lower level of accuracy than previously reported for those subjects trained in the NCS and (b) little difference in performance between the NCS‐ and Munsell‐trained groups.
    - jacobolus 7y ago
      What are you talking about? CSS has nothing to do with Munsell hues or NCS hues. I have no idea what you mean by “NSL”. The “HSL” / “HWB” hue circle is just a trivial transformation of the RGB cube (namely: zigzag along the 6 most colorful edges of the cube at constant speed), designed by non-color-expert computer programmers based on what was convenient to implement on workstation computers from the late 1970s (note: these considerations are not relevant 40 years later), and has almost nothing to do with human perception. It is nowhere near perceptually uniform (unlike the goals of Munsell hues), and also does not have human-perception-meaningful landmarks like the NCS cardinal directions. If you follow a circle of constant “W” and “B” in the “HWB” model, at constant speed in terms of “H”, then a typical human observer will see wildly varying “lightness”, “colorfulness”, “saturation”, “whiteness”, “blackness” with respect to their own perception, and will see perceived hue change at highly irregular and unsmooth speed.

floatingatoll 7y ago

The NCS image at the link you provide above literally shows the exact three-cornered orange-white-black triangle at position -Y10R that is shown in this image, which appears to use the exact hue sequence shown in your wiki link’s animation. I’m confused why you object to it being supported. Is your objection to their use of Hue spectrum positions 0,90,180,270 (R,G,C,M) - as already implemented in CSS today - as the four saturated qualia rather than NCS’s specified four qualia positions of 0,90,180,270 (R,Y,G,B)? HWB: https://commons.wikimedia.org/wiki/File:GTK_color_chooser.png https://commons.wikimedia.org/wiki/File:GTK_color_chooser.pn... NCS: https://commons.wikimedia.org/wiki/File:Animation_of_the_NCS_Colour_System.gif https://commons.wikimedia.org/wiki/File:Animation_of_the_NCS...

jacobolus 7y ago
It is emphatically not “literally the exact [...] triangle”. The NCS is a similar concept, but executed based on a plausible theoretical model and (more or less) sound empirical study of human perceptual response to visual stimuli. “HWB”, like HSL, is just someone’s trivial half-assed transformation of the RGB cube, completely ignoring more than a century of color science research. It’s what you get when a person off the street were tasked with redefining the NCS, without understanding it. It reminds me of people’s bicycle sketches, http://www.gianlucagimini.it/prototypes/velocipedia.html http://www.gianlucagimini.it/prototypes/velocipedia.html Personally I am not the biggest fan of the NCS system for designating colors; I find Munsell-like coordinate systems to work better for me, in practice. But at least it has some kind of theoretical and empirical basis.
- floatingatoll 7y ago
  This paper from a few years ago compares various mathematical definitions of "hue" that have been popular over the past few decades. https://pdfs.semanticscholar.org/7833/f96c09a1201f0e7f54e0de662e4faef36276.pdf https://pdfs.semanticscholar.org/7833/f96c09a1201f0e7f54e0de... CSS, having already standardized on Munsell hue circles (page 5) in the past, appears content to continue forward with them as the hue circle of choice for HWB. While I respect that you would prefer to see them use the NSL hue circle (pages 10-11), it appears that they are unlikely to do so at this time. One bonus find here is the abstract for the cited Whitfield (1988) paper, where the paper's authors attempted to replicate the assertion that NSL is better than Munsell, and failed: https://onlinelibrary.wiley.com/doi/10.1002/col.5080130210 https://onlinelibrary.wiley.com/doi/10.1002/col.5080130210 The study reported here is a replication of experiments cited as support for this claim. Subjects were trained in the NCS using NCS training material and carried out colour‐identification tasks. For comparison, a further subject group was trained in the Munsell system and carried out identical tasks. The results indicated (a) a lower level of accuracy than previously reported for those subjects trained in the NCS and (b) little difference in performance between the NCS‐ and Munsell‐trained groups.
  - jacobolus 7y ago
    What are you talking about? CSS has nothing to do with Munsell hues or NCS hues. I have no idea what you mean by “NSL”. The “HSL” / “HWB” hue circle is just a trivial transformation of the RGB cube (namely: zigzag along the 6 most colorful edges of the cube at constant speed), designed by non-color-expert computer programmers based on what was convenient to implement on workstation computers from the late 1970s (note: these considerations are not relevant 40 years later), and has almost nothing to do with human perception. It is nowhere near perceptually uniform (unlike the goals of Munsell hues), and also does not have human-perception-meaningful landmarks like the NCS cardinal directions. If you follow a circle of constant “W” and “B” in the “HWB” model, at constant speed in terms of “H”, then a typical human observer will see wildly varying “lightness”, “colorfulness”, “saturation”, “whiteness”, “blackness” with respect to their own perception, and will see perceived hue change at highly irregular and unsmooth speed.