HueCorrect

Lets you make precision adjustments to the levels of saturation in a range of hues. You do so via edits to a series of suppression curves. The horizontal axis represents the original, or input, saturation, and the vertical axis represents the new, or output, saturation.

By choosing which curve you edit and how much of that curve you alter, you can precisely limit the influence of the effect.

For the compositor, HueCorrect is obviously of greatest use in diminishing green, blue, or redscreen spill.

For the times when you just want to correct the saturation component and don’t require limiting the correction to any particular range of hues, you can also use the Saturation node.

Inputs and Controls

Connection Type

Connection Name

Function

Input

unnamed

The image sequence to correct.

mask

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

HueCorrect Tab

channels

channels

rgb

The correction 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.

curve editor

hue

N/A

Use the curves to adjust the hue of the input image. You can also look up color information for the current pixel in the Viewer.

reset

N/A

N/A

Click to reset the curves to the default values.

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 correction is 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 correction is 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 correction 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 HueShift 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 luminance

N/A

enabled

Enables the mix luminance slider. Disabling this checkbox is the same as setting mix luminance to 0.

mix_luminance

0

Controls how much of the original luminance is preserved after the color correction. A value of 0 means the altered luminance is used in the output image. A value of 1 produces a luminance value close to that of the original input image.

mix

mix

1

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

Step-by-Step Guides

Correcting Hue Only