4 ms·

Interesting. Can you provide source about normalization? I thought CIELab and CIELuv spaces use some form of average human perception correction factor. At a gi

Interesting. Can you provide source about normalization? I thought CIELab and CIELuv spaces use some form of average human perception correction factor. At a given luminosity, it should be the same regardless of the orthogonal chromaticity axis for an average human. Matplotlib’s colormaps were generated similarly: https://m.youtube.com/watch?v=xAoljeRJ3lU https://m.youtube.com/watch?v=xAoljeRJ3lU

deltron3030 6y ago
Compare the colors: http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#0d96f0,6c93c5 http://davidjohnstone.net/pages/lch-lab-colour-gradient-pick... Doesn't the one with 54 chromacity appear much brighter to you than the one with a chomacity of 30?
- trevyn 6y ago
  It's clearly and intentionally more vibrant, which can be a synonym for "brighter", but no, it does not seem particularly more luminant. Squinting very hard may help you see this. Another way is to overlap the two colors with interleaving stripes, and see how adjusting the chrominance differs perceptually from adjusting the luminance.
  - deltron3030 6y ago
    But that's just theory, in practice users don't squint their eyes when they use your UI, meaning that in practice perceived brightness does matter, less how it comes about.
    - spectramax 6y ago
      Isn’t the perceived brightness depend on surrounding colors and many other variables such as motion, incident illumination, etc? Those things cannot be part of a specification such as CIE or NCS.
      - deltron3030 6y ago
        My point was that luminance and chromacity fulfill a very similar function in UI design besides size or shadows, they bring elements forward, make them stand out. An item with low chromacity therefore isn't on the same Z level as an item with high chromacity if you think of the foreground and background as a 3d space that you can use to guide the eyes of users. It's the function for the user experience that counts, at least for me.
        spectramax 6y ago
        Thanks for the discussion, I learned about the NCS system and you seem to know a lot about this.
    - trevyn 6y ago
      For psychological impact use of "brightness", yes. For judging contrast against e.g. text for legibility in a design?
- spectramax 6y ago
  Squint eyes and they’re the same to me. https://classicalatelierathome.com/squint-your-eyes https://classicalatelierathome.com/squint-your-eyes Yeah it does appear “brighter” otherwise but I postulate that it is not possible to come up with 2 colors of same chromacity but with different “brightness” (your definition). Also, I hope the colors are not being cut off because of sRGB or P3 gamut on your PC or phone.

deltron3030 6y ago

Compare the colors: http://davidjohnstone.net/pages/lch-lab-colour-gradient-picker#0d96f0,6c93c5 http://davidjohnstone.net/pages/lch-lab-colour-gradient-pick... Doesn't the one with 54 chromacity appear much brighter to you than the one with a chomacity of 30?

trevyn 6y ago
It's clearly and intentionally more vibrant, which can be a synonym for "brighter", but no, it does not seem particularly more luminant. Squinting very hard may help you see this. Another way is to overlap the two colors with interleaving stripes, and see how adjusting the chrominance differs perceptually from adjusting the luminance.
- deltron3030 6y ago
  But that's just theory, in practice users don't squint their eyes when they use your UI, meaning that in practice perceived brightness does matter, less how it comes about.
  - spectramax 6y ago
    Isn’t the perceived brightness depend on surrounding colors and many other variables such as motion, incident illumination, etc? Those things cannot be part of a specification such as CIE or NCS.
    - deltron3030 6y ago
      My point was that luminance and chromacity fulfill a very similar function in UI design besides size or shadows, they bring elements forward, make them stand out. An item with low chromacity therefore isn't on the same Z level as an item with high chromacity if you think of the foreground and background as a 3d space that you can use to guide the eyes of users. It's the function for the user experience that counts, at least for me.
      - spectramax 6y ago
        Thanks for the discussion, I learned about the NCS system and you seem to know a lot about this.
  - trevyn 6y ago
    For psychological impact use of "brightness", yes. For judging contrast against e.g. text for legibility in a design?
spectramax 6y ago
Squint eyes and they’re the same to me. https://classicalatelierathome.com/squint-your-eyes https://classicalatelierathome.com/squint-your-eyes Yeah it does appear “brighter” otherwise but I postulate that it is not possible to come up with 2 colors of same chromacity but with different “brightness” (your definition). Also, I hope the colors are not being cut off because of sRGB or P3 gamut on your PC or phone.