Houdini 20.5 Nodes Copernicus nodes

Contrast Copernicus node

Applies contrast to a layer.

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This node applies contrast to a layer. This pushes values away from a central value when contrast is increased, or pulls them back to that value when contrast is decreased.

Parameters

Signature

The layer type that the source accepts.

See Signatures for more information.

Mask

The amount of the new value to mix in with the original value. Higher values mix in more of the new value. Lower values mix in less of the new value. You can also set the RGBA channels to which you apply the effects of this node.

The default value is 1, which means this node uses only the new value. See Mask for more information.

Toggle RGB

Turns the Red, Green, and Blue channels on and off.

Red (default)

Applies this node’s effects to the Red channel.

Green (default)

Applies this node’s effects to the Green channel.

Blue (default)

Applies this node’s effects to the Blue channel.

Alpha (default)

Applies this node’s effects to the Alpha channel.

Contrast

How much contrast to apply. 1 will leave the image unchanged. Larger values will brighten light areas and darken dark areas, and lower values will do the opposite. 0 will cause all values to be the contrast center.

Contrast Center

The pivot around which contrast will occur.

Red

Contrast and offset pair to apply to the red channel.

Green

Contrast and offset pair to apply to the green channel.

Blue

Contrast and offset pair to apply to the blue channel.

Alpha

Contrast and offset pair to apply to the alpha channel.

Clamp Below Zero

Black values will be pushed into negative values, but often negative light isn’t reasonable, so this will clamp them at zero.

Clamp Above One

White areas can be pushed beyond one, which is reasonable for HDR images, but if applying contrast to a mask it may be desireable to limit the growth to 1.

Treat RGBA as Premultiplied

RGBA layers are often premultiplied, so using a fixed pivot that doesn’t take the alpha into consideration will cause low coverage areas to be considered dark. This option will implicitly un-premultiply, contrast, and then pre-multiply, so the pivot works as expected.

Inputs

source

The layer to apply contrast to.

contrast

An optional per-mono per-pixel layer to scale the amount of contrast. This is multiplied with the Contrast parameter.

mask

An optional per-pixel mask amount that’s scaled by the Mask parameter.

Outputs

contrast

The layer with contrast applied.

See also

Copernicus nodes