# Noise node¶

*This documentation is for version 2.0 of Noise.*

## Description¶

Add random noise to input stream.

Note that each render gives a different noise.

Uses the ‘noise’ function from the CImg library.

CImg is a free, open-source library distributed under the CeCILL-C (close to the GNU LGPL) or CeCILL (compatible with the GNU GPL) licenses. It can be used in commercial applications (see http://cimg.eu).

## Inputs¶

Input | Description | Optional |
---|---|---|

Source | Yes | |

Mask | Yes |

## Controls¶

Parameter / script name | Type | Default | Function |
---|---|---|---|

Sigma / `sigma` |
Double | 0.01 | Amplitude of the random additive noise. |

Type / `type` |
Choice | Gaussian | Type of additive noise.
Gaussian: Gaussian noise.Uniform: Uniform noise.Salt & Pepper: Salt & pepper noise.Poisson: Poisson noise. Image is divided by Sigma before computing noise, then remultiplied by Sigma.Rice: Rician noise. |

(Un)premult / `premult` |
Boolean | Off | Divide the image by the alpha channel before processing, and re-multiply it afterwards. Use if the input images are premultiplied. |

Invert Mask / `maskInvert` |
Boolean | Off | When checked, the effect is fully applied where the mask is 0. |

Mix / `mix` |
Double | 1 | Mix factor between the original and the transformed image. |