GreyScale

AviSynth+
Up-to-date documentation: https://avisynthplus.readthedocs.io

Converts the input clip to greyscale (no color), without changing the color format.

UK (Greyscale) and US (Grayscale) spellings are both allowed.

Greyscale(clip clip [, string matrix])
Grayscale(clip clip [, string matrix])

string  matrix = "Rec601"

In RGB based formats, the conversion produces the luma using the coefficients given in the matrix parameter.

• "Rec601" : Use Rec.601 coefficients (and keeping luma range unchanged)
• "Rec709" : Use Rec.709 (HD) coefficients (and keeping luma range unchanged)
• "Rec2020" : Use Rec.2020 (UHD) coefficients (and keeping luma range unchanged) AVS+
• "AVERAGE" : Use averaged coefficients (Y = (R + G + B) / 3)

If clip is YUV, the chroma channels are simply set to grey (128_d) – matrix is not used and must not be specified otherwise an error will be thrown.

See Color conversions for an explanation of the coefficients. Broadly speaking though,

• using Rec709, green contributes more to the output, compared to the default Rec601;
• using Average, blue contributes more.

In all cases, Luma range is not changed (0_d-255_d in → 0_d-255_d out; 16_d-235_d in → 16_d-235_d out)