Albedo image map to color's Light Reflectance Value (LRV) In many datasets in the literature of both Computer Vision and Computer Graphics there is the albedo map of a scene represented as RGB images, which in principle corresponds to the diffuse reflecting component. The diffuse reflectance factor though of a material/surface is represented a one value, usually as ρ (rho), e.g. in the radiosity formulation. Thus, I am trying to understand how to go from an RGB representation to the corresponding diffuse value. I saw some people averaging the RGB values of the albedo map, e.g. for a pixel value (0, 168, 170) this would give:
((0/255) + (168/255) + (170/255)) / 3 = 0.441830065359477
however is just averaging enough/correct or there is a specific formulation.
I am puzzled quite some time now about it and I cannot really find a good answer. Thus, I would appreciate any feedback.
I am not aware of what LRV is and what is a usage of it. However, I can recommend using luma instead of simply averaging RGB values with equal weight:

https://en.wikipedia.org/wiki/Luma_(video)
https://en.wikipedia.org/wiki/Relative_luminance
Example of using luma - http://blog.simonrodriguez.fr/articles/30-07-2016_implementing_fxaa.html

Human eyes are more sensitive to green colors [1], that's why 16 bit (aka high color [2]) palettes, might prefer to use R5G6B5 format.
[1] https://en.wikipedia.org/wiki/Color_vision
[2] https://en.wikipedia.org/wiki/High_color