Crosstalk

Adds or removes crosstalk, or bleeding, from one color channel to another. Each output color channel is the sum of three lookup tables, each indexed by one of the input color channels. The horizontal axis represents the channel’s original, or input, values, and the vertical axis represents the channel’s new, or output values.

Inputs and Controls

Connection Type

Connection Name

Function

Input

unnamed

The image whose color you want to adjust.

mask

An optional image to use as a mask. By default, the effects 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

Crosstalk Tab

[crossover curves]

crossover

N/A

From the curve list on the left, select the curve you want to modify.

For example, you’d select red to only modify the red values.

You can also select R->G, for example, to use the red value to evaluate the curve and add the result to the green value. Adjust the curve as necessary. To insert points on the curve, Ctrl/Cmd+Alt+click on the curve.

Reset

N/A

N/A

Resets the selected curves to their initial positions.

mask

N/A

disabled

Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.

maskChannelInput

none

The channel to use as a mask. By default, the effects are limited to the non-black areas of this channel.

inject

inject

disabled

Copies 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

Inverts the use of the mask channel so that the effects are limited to the non-white areas of the mask.

fringe

fringe

disabled

When enabled, only apply the effect to the edge of the mask.

When disabled, the effect is applied to the entire mask.

(un)premult by

N/A

disabled

Enables the associated channel to the right. Disabling this checkbox is the same as setting the channel to none.

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 applying the expressions 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

Inverts the use of the (un)premultiply channel.

mix

mix

1

Dissolves between the original image at 0 and the full effect at 1.