Gamma correction vs. linear workflow

1 What is Gamma correction? the 8-bit luminance value x (0-1) passes through a x^0.45 of a brightening process.

2 Why Gamma correction is required

0.2gamma correction, 8 bit brightness, only 286gamma after correction, the original 0.20.5.

　　

It is important to note that the modern 8 -bit images are preserved by Gamma correction. Second , the image can save a lot of information, so do not need to go through Gamma correction.

3 What is a linear workflow

8 -bit brightness of the picture after the anti- Gamma correction, is the original x^0.45^2.2, simply speaking, the original after the 0.45 , and now go through the 2.2 to the x -square into a linear, then mixed with the light to produce the final color.

Gamma can be seen as a brightening process, and an anti- gamma process.

4 Why you need a linear workflow

Because in the game engine or 3D rendering software, the light is a linear amount, when the light and non- Gamma correction of nonlinear texture data mixed There are two cases, one is the texture brightness is right, but the light will feel the local exposure is too high, and the distance is too dark, Second, the light is displayed correctly, but the texture is brighter and the luminance details are lost. Why this, the first case, the light also added anti- Gamma, so that the dark position is darker, the light position is too bright in contrast, the second case, the texture was again a Gamma, so brighter, and the human eye on the 0-0.2 and 0.2-1 Feeling is the same color difference, the brightness difference is higher, but people can not see, and the dark difference becomes smaller, will feel the brightness detail loss is obvious.

Then it is only a process of anti-Gamma before mixing with the light, so that the light and texture data are linear data and are displayed correctly.

Gamma correction vs. linear workflow