Definition of luminance in English:



  • 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.’
    • ‘This principal component direction is taken to be the luminance direction.’
    • ‘Nits are also a measure of luminance, in so many candela per square metre.’
    1. 1.1The component of a television signal that carries information on the brightness of the image.
      • ‘These signals are also what is referred to as Y / C signal or luminance and chrominance.’
      • ‘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.’
      • ‘It is thus possible to quickly restore the light quantity control function by inputting the current luminance signal to an iris controller before the display of the still picture is stopped.’
      • ‘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).’


Late 19th century (as a general term meaning light, brightness): from Latin luminant- illuminating (from the verb luminare) + -ance.