Houdini 20.5 Nodes Copernicus nodes

Equalize Copernicus node

Equalizes colors by stretching or shifting their range.

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This node adjusts colors by shifting or scaling them. You can use this node to re-anchor the colors or make them fit a given range.

This node is useful when you need to fit an unknown input range into a specific range.

Note

Changes to the input can cause unwanted effects in procedural setups if some frames suddenly have extreme values. This means it’s usually better to use a Remap COP with a fixed range. The Remap COP is also faster because it doesn’t do the range computation.

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.

Equalize By

The method used to equalize the colors.

Stretch to Black and White

Map the minimum and maximum values found in the image to the Black and White values.

Move Minimum to Black

Adjust the colors so the minimum value is the Black value.

Move Maximum to White

Adjust the colors so the maximum value is the White value.

Move Average to Value

Adjust the colors so the average luminance matches the given Target Average.

Scale to Maximum Length

Scale the colors so the maximum luminance matches the given White value.

Fit Method

The method used to move a certain color to a goal value.

Note

This parameter doesn’t apply when Equalize By is set to Stretch to Black and White or Scale to Maximum Length.

Shifting Values

Match the goal value by adding the difference to all pixels.

Scaling Values

Match the goal value by scaling all pixels by the ratio.

Luminance Type

The luminance type to apply to the colors.

SGI Luminance

This is a historical luminance computation used in Houdini, which is believed to originate with SGI.

lum = 0.3086 * red + 0.6094 * green + 0.0820 * blue

NTSC Luminance

The standard NTSC luminance computation, which is a common luminance option.

lum = 0.299 * red + 0.587 * green + 0.114 * blue

HDTV Luminance

The HDTV standard luminance from BT 709.

lum = 0.2126 * red + 0.7152 * green + 0.0722 * blue

Average

An average of the channels.

Maximum Channel

The maximum of the channels.

Minimum Channel

The minimum of the channels.

Magnitude / Length

The length of the vector formed by taking the channels as components. For a mono input, this is the absolute value.

Hue

Convert to HSV and return the hue channel.

Saturation

Convert to HSV and return the saturation channel.

Value

Convert to HSV and return the value channel.

Red

Extract the red, or x, channel.

Green

Extract the green, or y, channel.

Blue

Extract the blue, or z, channel.

Alpha

Extract the alpha, or w, channel.

Black

The value to use for black, which is usually 0.

White

The value to use for white, which is usually 1.

Target Average

When Equalize By is Move Average to Value, this is the goal average value.

Inputs

source

The layer to equalize.

active

An optional layer of pixels that contribute to computing the range of the equalization. Pixels with a value greater than 0.5 are considered.

mask

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

Outputs

equalize

The equalized layer.

See also

Copernicus nodes