F_ReGrain

F_ReGrain is used to add grain to a sequence. It is designed to sample an area of grain from one image and then to generate unlimited amounts of this grain with exactly the same statistics as the original. This new grain can then be applied to another image.

Inputs and Controls

Connection Type	Connection Name	Function
Input	Grain	The image from which grain is sampled. When a Grain input is supplied, F_ReGrain automatically switches to using grain sampled from this input. However, the supplied grain stocks are still available.
Input	Src	The image to which the grain is added.

Control (UI)	Knob (Scripting)	Default Value	Function
F_ReGrain Tab
Grain Type	grainType	Preset Stock	Selects whether the grain is sampled from the Grain input or from a set of standard stocks. • Preset Stock - grain characteristics are sampled from the film stock specified in the Preset Stock field. • From Grain Clip - samples and reconstructs the grain characteristics from the Grain input.
Preset Stock	presetStock	FUJIF250under 2K	The film stock that grain characteristics are sampled from when GrainType is set to PresetStock.
Grain Amount	amount	1	Adjusts the brightness of the grain. Setting this to 0 adds no grain.
Grain Size	size	1	Adjusts the size of the grain granules. The larger the value, the bigger and softer the granules.
Output	output	Result	Sets whether to render the result or a test image. • Result - shows the Src input with the grain applied. • Grain Plate - shows a test image with the grain applied. This test image is composed from a section of the input image surrounded by a uniform solid color sampled from the image with the grain applied. If the inner area is indistinguishable from the outer area, then you have a good grain sample.
Analyse	analyse	N/A	Click to begin analysis of the source. Press this button if the input clip from which the grain was analyzed has changed, but you do not want to move the analysis region to trigger re-analysis. Note: A warning displays when the input clip changes.
Analysis Region
Analysis Region BL	regionBL	N/A	A selection box that marks the region of image used to analyze the grain when GrainType is set to From Grain Clip. This part of the frame must contain no image detail, only grain. • Analysis Region BL - controls the position of the bottom left corner of the analysis region. • Analysis Region TR - controls the position of the top right corner of the analysis region.
Analysis Region TR	regionTR	N/A
Analysis Frame	frame	1	Sets the frame to sample the grain from.
Grain Colour Space	grainColourSpace	sRGB	This tells F_ReGrain what color space the grain sample clip was in when the grain originated. Setting this correctly ensures that the grain is not exaggerated by any color space conversions prior to sampling. • Cineon • sRGB • Linear
Advanced
Process Red	processRed	enabled	Disable this if you do not want to process the red channel.
Red Amount	redAmount	1	Sets the brightness of the grain in the red channel.
Red Size	redSize	1	Adjusts the size of the grain granules in the red channel.
Process Green	processGreen	enabled	Disable this if you do not want to process the green channel.
Green Amount	greenAmount	1	Sets the brightness of the grain in the green channel.
Green Size	greenSize	1	Adjusts the size of the grain granules in the green channel.
Process Blue	processBlue	enabled	Disable this if you do not want to process the blue channel.
Blue Amount	blueAmount	1	Sets the brightness of the grain in the blue channel.
Blue Size	blueSize	1	Adjusts the size of the grain granules in the blue channel.
Advanced > Grain Response
Apply Grain In	srcColourSpace	Grain Colour Space	Sets what color space the grain sample is re-applied to the image: • Cineon / sRGB / Linear - the grain sample is applied in the specified space. • Grain Colour Space - the grain sample is applied in the color space set in the Analysis Range > Grain Colour Space field.
Low Gain	lowGain	1	Adjusts the gain of the grain in the lowlights.
Mid Gain	midGain	1	Adjusts the gain of the grain in the midtones.
High Gain	highGain	1	Adjusts the gain of the grain in the highlights.
Use Sampled Response	useResponse	disabled	Enable this control to scale the brightness of the grain as a function of the luminance of the Grain image.
Sampled Response Mix	responseMix	1	Decreasing the Sampled Response Mix control reduces the effect of the response curves until, at 0, they have no effect on the output. Note: This control is only available if Use Sampled Response is enabled.
Sample Grain Response	sample	N/A	Click to update the response curves from the current frame. Multiple clicks accumulate the grain response rather than resetting every time. Note: This control is only available if Use Sampled Response is enabled.
Reset Grain Response	reset	N/A	Click to reset the grain curves to their default (flat) response. Note: This control is only available if Use Sampled Response is enabled.
Draw Response	drawResponse	disabled	Overlay the response curves on the bottom left corner of the viewer. Note: This control is only available if Use Sampled Response is enabled.
About	about	N/A	Displays a dialog containing information about this node.

Step-by-Step Guides

Using F_ReGrain