luminance
/ˈluːmɪn(ə)ns
/noun [mass noun] Physics
1The intensity of light emitted from a surface per unit area in a given direction.The specifications are commonly based on the 2 - D illuminance, luminance, intensity, chromaticity, and polarization distributions....
- Nits are also a measure of luminance, in so many candela per square metre.
- This principal component direction is taken to be the luminance direction.
1.1The component of a television signal which carries information on the brightness of the image.The Y component is the luminance of the signal (not the color yellow), and delivers the gray scale image....
- Note that the green channel has twice the number of photodetectors as red or blue (this is because the majority of luminance information is carried in the green channel).
- A sequence of passes separates the luminance and chrominance information from the composite video signal and demodulates the color carrier to separate out color information.
Origin
Late 19th century (as a general term meaning 'light, brightness'): from Latin luminant- 'illuminating' (from the verb luminare) + -ance.