Luminance.nk

set cut_paste_input [stack 0]
version 12.0 v8
push $cut_paste_input
Expression {
 temp_name0 L
 temp_expr0 w.0*r+w.1*g+w.2*b
 channel0 rgba
 expr0 L
 channel1 none
 channel2 none
 channel3 none
 name Luminance_Weights
 selected true
 xpos -2350
 ypos 80
 addUserKnob {20 Param}
 addUserKnob {35 weight_presets l "" +STARTLINE M {weights/ACEScg "knobs this \{w \{0.26806405 0.67246455 0.05947147\}\}" weights/Rec.2020 "knobs this \{w \{0.26270026 0.67799819 0.05930173\}\}" weights/Rec.2020_CIE_2015 "knobs this \{w \{0.25938492 0.60792035 0.13269473\}\}" weights/P3D65 "knobs this \{w \{0.22897467 0.69173867 0.07928693\}\}" weights/Rec.709 "knobs this \{w \{0.21263911 0.71516877 0.07219233\}\}" "weights/Red WideGamut RGB" "knobs this \{w \{0.28669411 0.84297919 -0.12967324\}\}" "weights/Alexa Wide Gamut" "knobs this \{w \{0.2919538 0.82384098 -0.11579483\}\}" "weights/Sony S-Gamut3.Cine" "knobs this \{w \{0.21507585 0.88506854 -0.10014433\}\}" "weights/Filmlight E-Gamut" "knobs this \{w \{0.28013074 0.82020682 -0.10033739\}\}" "weights/DaVinci Wide Gamut" "knobs this \{w \{0.27411851 0.87363189 -0.14775042\}\}"}}
 addUserKnob {78 w l "" t "luminance weighting" -STARTLINE n 3}
 w {0.26270026 0.67799819 0.05930173}
}