SeGrain node — Natron 2.5.0 documentation

# SeGrain node

This documentation is for version 1.0 of SeGrain (net.sf.openfx.SeGrain).

## Description

Adds synthetic grain.

Push “presets” to get predefined types of grain, these are the correct size for 2K scans.

You can also adjust the sliders to match a sample piece of grain. Find a sample with a rather constant background, blur it to remove the grain, and use as input to this. View with a wipe in the viewer so you can make a match. It helps to view and match each of the red, green, blue separately.

See also http://opticalenquiry.com/nuke/index.php?title=Integration#Matching_grain

## Inputs

Input | Description | Optional
--- | --- | ---
Source |  | No
Mask |  | Yes

## Controls

Parameter / script name | Type | Default | Function
--- | --- | --- | ---
Seed / `grainSeed` | Double | 134 | Change this value to make different instances of this operator produce different noise.
Static Seed / `staticSeed` | Boolean | Off | When enabled, the seed is not combined with the frame number, and thus the effect is the same for all frames for a given seed number.
Presets / `grainPresets` | Choice | Kodak 5248 | Presets for common types of film. Kodak 5248 Kodak 5279 Kodak FX214 Kodak GT5274 Kodak 5217 Kodak 5218 Other
All / `grainSizeAll` | Double | 1 | Global factor on grain size. Useful if working with scans which are not 2K (the preset sizes are computed for 2K scans).
Red / `grainSizeRed` | Double | 3.3 | Red grain size (in pixels).
Green / `grainSizeGreen` | Double | 2.9 | Green grain size (in pixels).
Blue / `grainSizeBlue` | Double | 2.5 | Blue grain size (in pixels).
Red / `grainIrregularityRed` | Double | 0.6 | Red grain irregularity.
Green / `grainIrregularityGreen` | Double | 0.6 | Green grain irregularity.
Blue / `grainIrregularityBlue` | Double | 0.6 | Blue grain irregularity.
Red / `grainIntensityRed` | Double | 0.42 | Amount of red grain to add to a white pixel.
Green / `grainIntensityGreen` | Double | 0.46 | Amount of green grain to add to a white pixel.
Blue / `grainIntensityBlue` | Double | 0.85 | Amount of blue grain to add to a white pixel.
Correlation / `colorCorr` | Double | 0 | This parameter specifies the apparent colorfulness of the grain. The value represents how closely the grain in each channel overlaps. This means that negative color correlation values decrease the amount of overlap, which increases the apparent color of the grain, while positive values decrease its colorfulness.
Black / `grainBlack` | Color | r: 0 g: 0 b: 0 | Amount of grain to add everywhere.
Minimum / `grainMinimum` | Color | r: 0 g: 0 b: 0 | Minimum black level.
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.