Keywords: Graphics, Image Processing, Color Science, RGB, Grayscale

References

Grayscale
https://en.wikipedia.org/wiki/Grayscale

Converting RGB to grayscale/intensity
https://stackoverflow.com/questions/687261/converting-rgb-to-grayscale-intensity

数字图像处理(18): 图像灰度变换——线性灰度变换 和 非线性灰度变换(对数变换 与 伽马变换)
https://blog.csdn.net/zaishuiyifangxym/article/details/89817995

Applications

Q: How to compute grayscale in UE4 Materials?
A: The dot product of a RGB color and a coefficient is grayscale, this value can be used to computing falloff.

and you can get a new color with grayscale modified by appending these individual channels.


Then he made one last effort to search in his heart for the place where his affection had rotted away, and he could not find it. ― Gabriel Garcia Marquez, One Hundred Years of Solitude