Gamma is a mathematical function that describes the relationship between the numerical pixel values in an image file and the actual brightness levels we perceive. This non-linear function typically follows a logarithmic curve, where the output brightness is proportional to the input raised to a specific power, known as the “gamma value.”
At its core, gamma describes how brightness values are distributed between the darkest and brightest parts of an image. Think of it as a mathematical relationship between what your camera captures and what appears on your screen or in prints.
Understanding Gamma Values
Gamma values typically range from 0.1 to 4.0, with a value of 1.0 representing a linear relationship between input and output. Values below 1.0 result in a darker image, while those above 1.0 produce a brighter, more contrasty appearance.
Common gamma settings include:
- Computer monitors: typically 2.2
- Print media: usually 1.8
- Mobile devices: varies by manufacturer