The effect of gamma on perceived image quality

The effect of gamma, the exponent of the power function that characterizes luminance transfer, on perceptual image quality and on the strength of its underlying dimensions, brightness contrast and sharpness have been studied for complex black-and-white scenes, displayed on a TV monitor. Gamma was found to have a scene-independent optimum value that is higher than expected. This optimum was found to be uniquely determined by (subjective) brightness contrast. Although (subjected) sharpness is influenced by gamma, experiments show that no interaction is to be expected in the range of interest. The results also show that luminance contrast ratio is an adequate measure of brightness contrast.<>