# SmoothBilateralGuided node¶

*This documentation is for version 2.0 of SmoothBilateralGuided.*

## Description¶

Apply joint/cross bilateral filtering on image A, guided by the intensity differences of image B. Uses the ‘blur_bilateral’ 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 |
---|---|---|

Guide | The guide image indicates where similar pixels are located in each neighborhood. The neighborhood of a pixel consists of pixels that are within a neighborhood of side sigma_s, which have an intensity/value in the Guide image that is within a range of size sigma_r around the intensity of the considered pixel. | No |

Source | No |

## Controls¶

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

Spatial Std Dev / `sigma_s` |
Double | 10 | Standard deviation of the spatial kernel (positional sigma), in pixel units (>=0). A reasonable value is 1/16 of the image dimension. Small values (1 pixel and below) will slow down filtering. |

Value Std Dev / `sigma_r` |
Double | 0.3 | Standard deviation of the range kernel (color sigma), in intensity units (>=0). A reasonable value is 1/10 of the intensity range. In the context of denoising, Liu et al. (“Noise estimation from a single image”, CVPR2006) recommend a value of 1.95*sigma_n, where sigma_n is the local image noise. Small values (1/256 of the intensity range and below) will slow down filtering. |

Iterations / `iterations` |
Integer | 2 | Number of iterations. |

(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. |