How is gamma handled in video, computer graphics, and desktop computing?
As outlined above, gamma correction in video effectively codes into a perceptually uniform domain. In video, a 0.45-power function is applied at the camera, as shown in the top row of this diagram: Synthetic computer graphics calculates the interaction of light and objects. These interactions are in the physical domain, and must be calculated in linear-light values. It is conventional in computer graphics to store linear-light values in the framebuffer, and introduce gamma correction at the lookup table at the output of the framebuffer. This is illustrated in the second row. If linear-light is represented in just eight bits, near black the steps between codes will be perceptible as banding in smoothly-shaded images. This is the eight-bit bottleneck in the sketch. Desktop computers are optimized neither for image synthesis nor for video. They have programmable “gamma” and either poor standards or no standards. Consequently, image interchange among desktop computers is fraught with diffi
As outlined above, gamma correction in video effectively codes into a perceptually uniform domain. In video, a 0.45-power function is applied at the camera, as shown in the top row of this diagram: Synthetic computer graphics calculates the interaction of light and objects. These interactions are in the physical domain, and must be calculated in linear-light values. It is conventional in computer graphics to store linear-light values in the framebuffer, and introduce gamma correction at the lookup table at the output of the framebuffer. This is illustrated in the middle row above. If linear-light is represented in just eight bits, near black the steps between codes will be perceptible as banding in smoothly-shaded images. This is the eight-bit bottleneck in the sketch. Desktop computers are optimized neither for image synthesis nor for video. They have programmable “gamma” and either poor standards or no standards. Consequently, image interchange among desktop computers is fraught with
