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Plug: I made a color space derived from CIE LUV to help generate colors procedurally. http://boronine.com/husl/ http://boronine.com/husl/

taliesinb 13y ago
Nice project. Do you know about HCL? http://hclcolor.com/ http://hclcolor.com/. There is also uniform perceptual LAB: http://www.brucelindbloom.com/index.html?UPLab.html http://www.brucelindbloom.com/index.html?UPLab.html which is a slight tweak to LAB to reduce the 'blue -> purple' effect that happens when you tweak chroma.
- jacobolus 13y ago
  UPLab is not a “slight tweak” of CIELAB. It’s a lookup table for going back and forth between CIELAB and a slightly rotated version of Munsell space, https://en.wikipedia.org/wiki/Munsell_color_system https://en.wikipedia.org/wiki/Munsell_color_system
  - taliesinb 13y ago
    You can look at it that way. You can also see it as a modification of cylindrical LAB. Explain your "slightly rotated" comment?
    - jacobolus 13y ago
      From Lindbloom’s site: “The mapping was done such that Munsell hue 2.5RP has a UP Lab hue angle of zero degrees. This particular rotation was chosen to allow greater chroma encoding of blue colors in the lower right quadrant of the a/b plane.” Also, to be completely precise, it should be noted that the lightness dimension of UPLab was left the same as CIELAB’s lightness, rather than using Munsell value. Only a and b were adjusted to reflect Munsell hue/chroma.
- boronine 13y ago
  Thanks! I could find little information on HCL, but based on this blog post [0] it seems that it is a cylindrical version of CIE LUV. This is the color space that HUSL is based on. What HUSL does is it replaces the chroma component with a saturation component that is defined as a percentage ranging from 0 to the maximum chroma for the given hue and lightness. To put it in another way, it stretches the chroma component to make it fit into a nice rectangle. This makes all components bounded and lets us pick color without stepping outside of the gamut. UPLab looks cool, thanks for sharing. [0] http://cscheid.net/blog/hcl_color_space_blues http://cscheid.net/blog/hcl_color_space_blues

taliesinb 13y ago

Nice project. Do you know about HCL? http://hclcolor.com/ http://hclcolor.com/. There is also uniform perceptual LAB: http://www.brucelindbloom.com/index.html?UPLab.html http://www.brucelindbloom.com/index.html?UPLab.html which is a slight tweak to LAB to reduce the 'blue -> purple' effect that happens when you tweak chroma.

jacobolus 13y ago
UPLab is not a “slight tweak” of CIELAB. It’s a lookup table for going back and forth between CIELAB and a slightly rotated version of Munsell space, https://en.wikipedia.org/wiki/Munsell_color_system https://en.wikipedia.org/wiki/Munsell_color_system
- taliesinb 13y ago
  You can look at it that way. You can also see it as a modification of cylindrical LAB. Explain your "slightly rotated" comment?
  - jacobolus 13y ago
    From Lindbloom’s site: “The mapping was done such that Munsell hue 2.5RP has a UP Lab hue angle of zero degrees. This particular rotation was chosen to allow greater chroma encoding of blue colors in the lower right quadrant of the a/b plane.” Also, to be completely precise, it should be noted that the lightness dimension of UPLab was left the same as CIELAB’s lightness, rather than using Munsell value. Only a and b were adjusted to reflect Munsell hue/chroma.
boronine 13y ago
Thanks! I could find little information on HCL, but based on this blog post [0] it seems that it is a cylindrical version of CIE LUV. This is the color space that HUSL is based on. What HUSL does is it replaces the chroma component with a saturation component that is defined as a percentage ranging from 0 to the maximum chroma for the given hue and lightness. To put it in another way, it stretches the chroma component to make it fit into a nice rectangle. This makes all components bounded and lets us pick color without stepping outside of the gamut. UPLab looks cool, thanks for sharing. [0] http://cscheid.net/blog/hcl_color_space_blues http://cscheid.net/blog/hcl_color_space_blues