RolloffContrast

Applies a contrast curve, with smooth falloff at the low and high ends, equally across all channels in the input image. The center value controls the overall brightness of the colors and the contrast value increases or decreases the contrast of the image. Use soft clip to control the amount of rolloff and check override values to adjust the tension and extent of the soft clip curve.

Inputs and Controls

Connection Type	Connection Name	Function
Input	unnamed	The image sequence to receive the rolloff.
mask	An optional image to use as a mask. By default, the contrast changes are limited to the non-black areas of the mask. At first, the mask input appears as triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Connection Type

Connection Name

Function

Input

unnamed

The image sequence to receive the rolloff.

mask

An optional image to use as a mask. By default, the contrast changes are limited to the non-black areas of the mask.

At first, the mask input appears as triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)	Knob (Scripting)	Default Value	Function
RolloffContrast Tab
channels	channels	rgba	The effect is only applied to these channels. If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.
range	range	1	Values between 0 and the input value use a lookup table to reduce processing time.
contrast	contrast	1	Higher values increase the contrast. Values closer to 0 reduce the contrast.
center	center	0.5	The center value is located at the center of the contrast curve by default and controls the overall brightness of the colors.
soft clip	soft_clip	0	The amount of roll off from the linear curve near the ends, softening the effect of the contrast.
override values	value_override	disabled	If enabled, custom values below override the computed values.
slope mag 1 low shoulder	slope_mag_low1	0.80000001	A value from 0 to 1 that controls where the interior control points are in the bezier.
slope mag 2 low shoulder	slope_mag_low2	0.0025	A value from 0 to 1 that controls where the interior control points are in the bezier.
blank point percentage	black_low	1	A value from 0 to 1 that controls the location of the black point. Computed as the distance between the origin and the contrast line zero crossing.
slope mag 1 upper shoulder	slope_mag_high1	1	A value from 0 to 1 that controls where the interior control points are in the upper bezier.
slope mag 2 upper shoulder	slope_mag_high2	0.80000001	A value from 0 to 1 that controls where the interior control points are in the upper bezier.
white point percentage	white_high	1	A value from 0 to 1 that controls the location of the white point. Computed as the distance between the 1,1 point and the contrast line y = 0 crossing.
mask	N/A	disabled	Enable the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.
mask	maskChannelInput	none	The channel to use as a mask. By default, the contrast effect is limited to the non-black areas of this channel.
inject	inject	disabled	Copy the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.
invert	invert_mask	disabled	Invert the use of the mask channel, so that the contrast effect is is limited to the non-white areas of the mask.
fringe	fringe	disabled	Blur the edges of the mask.
(un)premult by	N/A	disabled	Enable the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.
(un)premult by	unpremult	none	The image is divided by this channel before being processed, and multiplied again afterwards. If you are using premultiplied input images, you may want to check (un)premult by and select rgba.alpha here. This will simulate adjusting the contrast before the premultiplication was done. It is the same as adding an Unpremult node before this node and a Premult node after, but allows you to work faster if you’re only using one color correct node. If you are using unpremultiplied input images, you should leave this set to none.
invert	invert_unpremult	disabled	Invert the use of the (un)premultiply channel.
mix	mix	1	Dissolve between the original image at 0 and the full effect at 1.