How to calculate luminance from rgb

1. How is luminance value calculated?
2. How is luminance color measured?
3. What is the basic proportion of RGB components for luminance?

How is luminance value calculated?

Alternatively, the luminance of a surface can be calculated from the formula L = E x § / ¹ where § is the luminance factor of the surface material and is read from a table of values. If the surface is diffuse then § can be replaced with "p", the diffuse reflection coefficient for the material.

How is luminance color measured?

A photometer measures the brightness (luminance) of visible light as it is perceived by the human eye. Colorimetry is the science of measuring color (chromaticity) as it is perceived by the human eye. Some instruments, such as a spot meter, can measure both luminance and chromaticity.

What is the basic proportion of RGB components for luminance?

Every RGB pixel computes to a 8 bit Luminance value between 0 and 255 (because 0.3 + 0.59 + 0.11 = 1.0). This weighting is required because we see Green well, much better than we see Blue. Saturated Blue is dark to the human eye, and it doesn't contribute much to perceived brightness.