D5928: Introducing Night Color - KWin's native blue light filter at nighttime

[Roman Gilg]

subdiff added a comment.


  In https://phabricator.kde.org/D5928#112339, @cfeck wrote:
  
  > The difference between gamma correction and color correction is that the former only uses three 1D LUTs, while the latter can use three 3D LUTs. In other words, gamma correction cannot tint your blue more green, while color correction can.
  
  
  Can you give a source for that definition of the two notions? When I look it up Wikipedia explains Color Correction as a way to change color values in a generic fashion. It's relatively broad. I haven't found a very specific definition like you. In contrast gamma correction is explained as the adjustment of the gamma of the light in general - i.e. all colors at once. You can influence the color balance though by varying the gamma of the separate gamma color channels, which is then again part of color correction. There is also the notion of color management, which is somewhat all of that as well in our context.
  
  > EDIT: We had code to do color correction, but that was deleted. For details, see the commit message.
  > 
  > https://cgit.kde.org/kwin.git/commit/?id=17e0bad922c7b9b17164987d2a4d64bff936edae
  
  Thanks for the link! Seems to be not relevant anymore, although the goal was somewhat the same as for my later planned color correction (using 1D LUTs), which is simpler but still better than nothing (also the prime objective was to offer the functionality of KGamma on Wayland, which uses 1D LUTs as well).

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D5928

To: subdiff, #kwin
Cc: cfeck, graesslin, davidedmundson, plasma-devel, kwin, ZrenBot, spstarr, progwolff, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, eliasp, sebas, apol, mart, hein, lukas
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