gammaEncode

gammaEncode is a technique used in computer graphics and image processing to prepare image data for display on devices with non-linear responses. Most display devices, such as monitors and televisions, do not accurately represent brightness linearly. Instead, they exhibit a gamma curve, meaning that a change in input signal does not result in a proportional change in output brightness.

Gamma encoding is the process of applying a mathematical function, typically a power-law function, to the pixel values of an image. This function compensates for the display device's inherent gamma response. By encoding the image with the inverse of the display's gamma curve, the image appears with the intended brightness and contrast when viewed on the display.

Without gamma encoding, images would appear darker or washed out depending on the display's gamma. For example, on a display with a gamma of 2.2, a linear image would appear too dark. Gamma encoding effectively "pre-distorts" the image data so that when it passes through the display's non-linear response, it is rendered correctly.

In practice, images are often stored in a gamma-corrected space (e.g., sRGB, which has an approximate gamma of 2.2). This means that the image data already incorporates the encoding for typical displays. When processing these images, it's often necessary to de-gamma them (convert them to a linear color space) for accurate calculations, and then re-gamma them before displaying. The term "gammaEncode" specifically refers to the act of applying this gamma correction, usually to prepare data for a display.