What is LUT

Lookup Table, or "LUT" for short, is a way to use a mapping texture to swap out on-screen pixel color swatch. Simply put, LUTs are color value mapping tables. No matter if the color value is observable or not, all values can be mapped out. The principle mechanism of LUT is to turn an RGB image to grayscale and then map the grayscale values to other RGB color values.

LUT's advantages include more convenient image conversion with better performance and more professional results.

You can set the color mapping in a 2D solution such as Photoshop, Gimp, etc. for more precise control.

Take the scene shown below as an example. With different LUT templates applied, you can create different feeling for that scene.

• The original scene:
  
• The scene applied with different LUT templates: