SmoothRollingGuidance node — Natron 2.5.0 documentation

# SmoothRollingGuidance node

This documentation is for version 2.0 of SmoothRollingGuidance (net.sf.cimg.CImgRollingGuidance).

## Description

Filter out details under a given scale using the Rolling Guidance filter.

Rolling Guidance is described fully in http://www.cse.cuhk.edu.hk/~leojia/projects/rollguidance/

Iterates 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
--- | --- | ---
Source |  | No
Mask |  | Yes

## Controls

Parameter / script name | Type | Default | Function
--- | --- | --- | ---
Spatial Std Dev / `sigma_s` | Double | 10 | Standard deviation of the spatial kernel, in pixel units (>=0). Details smaller than this size are filtered out.
Value Std Dev / `sigma_r` | Double | 0.1 | Standard deviation of the range kernel, 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.
Iterations / `iterations` | Integer | 4 | Number of iterations of the rolling guidance filter. 1 corresponds to Gaussian smoothing. A reasonable value is 4.
(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.