gammaDecode

gammaDecode refers to the process of reversing gamma correction, a non-linear operation used in image and video processing. Gamma correction is applied to adjust the brightness and contrast of images, often to compensate for the non-linear response of display devices. Gamma decoding, therefore, transforms image data back into a linear light intensity representation, which is necessary for accurate image analysis, manipulation, and display.

The gamma function is typically represented by the equation O = I^gamma, where I is the input intensity, O is the output intensity, and gamma is the gamma value. Gamma decoding reverses this by raising the input (which is already gamma-encoded) to the power of 1/gamma. So, the decoding equation is I_linear = O_gamma^(1/gamma).

In practical applications, gamma values are often around 2.2 for typical displays. When an image is captured, it might be gamma-encoded for display purposes. If this image is then used in software that expects linear light data, such as for 3D rendering or scientific analysis, a gamma decode step is crucial. Failure to perform gamma decoding can lead to incorrect calculations and visually distorted results. Many image processing libraries and graphics APIs provide functions to handle gamma correction and decoding automatically or allow manual control over the process. Understanding gamma decoding is essential for achieving accurate visual representation and correct image manipulation in various digital media workflows.