luminance

from WordNet (r) 3.0 (2006)

luminance
    n 1: the quality of being luminous; emitting or reflecting
         light; "its luminosity is measured relative to that of our
         sun" [syn: {luminosity}, {brightness}, {brightness level},
         {luminance}, {luminousness}, {light}]

from The Free On-line Dictionary of Computing (8 July 2008)

brightness
luminance
tone
value

   <graphics> (Or "tone", "luminance", "value", "luminosity",
   "lightness") The coordinate in the {HSB} {colour model} that
   determines the total amount of light in the colour.  Zero
   brightness is black and 100% is white, intermediate values are
   "light" or "dark" colours.

   The other coordinates are {hue} and {saturation}.

   (1999-07-05)