Gamma correction
![The effect of gamma correction on an image: The original image was taken to varying powers, showing that powers larger than 1 make the shadows darker, while powers smaller than 1 make dark regions lighter.](/Images/godic/202501/09/GammaCorrection_demo1859.jpg")
![Plot of the sRGB standard gamma-expansion nonlinearity (red), and its local gamma value, slope in log–log space (blue).](/Images/godic/202501/09/SRGB_gamma.svg1859.png")
![](/Images/godic/202501/09/Gammatest.svg1859.png")
Gamma correction, gamma nonlinearity, gamma encoding, or often simply gamma, is the name of a nonlinear operation used to code and decode luminance or tristimulus values in video or still image systems. Gamma correction is, in the simplest cases, defined by the following power-law expression: