A collection of 3D LUTs for colour-to-greyscale conversion in 64x64x64 HALD and x65 CUBE format.

https://github.com/janvancoppenolle/LUT/tree/main/BW%20Conversion

Input

Brightness

\[{r+ g + b \over 3}\]
Result

Luminance

\[0.2989 r + 0.587 g + 0.114 b\]
Result

Euclidean

\[\sqrt{ r^2 + g^2 + b^2 \over 3}\]
Result

sRGB Luma (Rec. 709)

\[0.2126r + 0.7152g + 0.0722b\]
Result

Multiply

\[(r+1) (g+1) (b+1) - 1 \over 7\]
Result

Screen

\[8 - (2-r) (2-g) (2-b) \over 7\]
Result

Lightness

\[min(r,g,b) + max(r,g,b) \over 2\]
Result

Middle

\[r+g+b-min(r,g,b)-max(r,g,b)\]
Result

Minimum

\[min(r,g,b)\]
Result

Maximum

\[max(r,g,b)\]
Result

Orthochromatic (Cyan Filter)

\[g + b \over 2\]
Result

Orthochromatic (Film Simulation)

\[max(g,{b \over 2})\]
Result