Definitions for "BRIGHTNESS RATIO"
The ratio between the light reflected by a region and the light reflected by the area that surrounds it. According to one theory, perceived brightness is determined by this ratio.
Difference between the brightest (whitest) and darkest (blackest) areas in an image. The wider the brightness ratio, the wider the contrast ratio.
The difference between the brightest and darkest object in a picture. Too much of a difference can cause unacceptable contrast.