 In the common case of , inputs and outputs are typically in the range 0–1.A gamma value formula_5 is sometimes called an "encoding gamma", and the process of encoding with this compressive power-law nonlinearity is called gamma compression; conversely a gamma value formula_6 is called a "decoding gamma" and the application of the expansive power-law nonlinearity is called gamma expansion.Gamma encoding of images is used to optimize the usage of bits when encoding an image, or bandwidth used to transport an image, by taking advantage of the non-linear manner in which humans perceive light and color.