Perceived quality and contrast as a function of gamma

The luminance reproduction curve of a TV system is characterized by a power function over a significant ran ge. The effect of the power gamma on perceptual image quality and on its dominant factor brightness contrast has been studied for still complex black-and-white scenes displayed on a TV monitor. Gamma was found to have a scene-dependent optimum value which is higher than expected. This optimum was found to be uniquely determined by (subjective) brightness contrast. The results also show that the ratio of the highest and lowest luminance in the scene is inadequate as a measure of brightness contrast of complex pictures.