Mono Copernicus node

Converts a layer to mono.

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Parameters
Inputs
Outputs

This node converts a layer into a mono layer, which is often done with a form of luminance computation. You can also use this node to extract a channel or grab the maximum channel, minimum channel, or the length of the channels treated as a vector.

If you want to extract a channel, you can use the Channel Extract COP instead of this node.

Parameters ¶

Signature

The layer type that the source accepts.

See Signatures for more information.

Operation

The method used to combine the source channels into the final value. The standard channel extension rules apply unless specified otherwise.

Note

Some luminance methods assume a source color space. No implicit conversion is done from your scene_linear to this space.

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.

Custom

Perform custom weighting of the channels. Use the Dot Product COP if you want this weighting to vary per pixel.

Weights

When Operation is Custom, this is the weight by which to multiply each channel before adding them up to get the luminance.

Normalize Weights

When Operation is Custom, this scales the provided weights by their total to make sure the total equals one.

Inputs ¶

source

The original layer to convert into a mono layer.

Outputs ¶

mono

The resulting mono layer created by combining the source values into a single channel.

See also

Copernicus nodes

Auto Stereogram

Generates an image with a 3D illusion.
Average

Takes the average of all input layers.
Blend

Blends two layers together.
Block Begin

Start of a block, containing its inputs.
Block End

End of a block, declaring its outputs.
Block to Geometry

Compiles a block and produces its geometry representation.
Blur

Applies a blur to a layer.
Bokeh

Creates a Bokeh effect by expanding each pixel by an aperture shape.
Bounding Rectangle

Finds the bounding rectangle of a mask.
Bright

Brightens a layer.
Camera Import

Creates a layer in a camera’s space.
Camera Properties

Adjusts the camera properties of a layer.
Channel Extract

Extracts a channel from a layer.
Channel Join

Combines multiple Mono layers into one multichannel layer.
Channel Split

Divides a layer’s channels into Mono layers.
Channel Swap

Swaps channels within a multichannel layer.
Checkerboard

Creates an alternating checker pattern.
Chladni Cymatic Patterns

Generates interference patterns that represent various vibration modes.
Chroma Key

Keys an input based on hue, saturation, and luminance ranges.
Chromatic Aberration

Adds chromatic aberration to your image.
Clamp

Clamps an input layer.
Combine Normals

Blends two normal maps together.
Compare

Creates a mask by comparing two layers.
Constant

Initializes pixels to constant values.
Contact Sheet

Arranges input layers into a contact sheet.
Contrast

Applies contrast to a layer.
Convert Normal

Converts normal layers between signed and offset.
Convolve 3×3

Convolves a layer by a 3×3 kernel.
Crop

Crops a layer to a new size.
Cross Product

Performs a cross product of two RGB layers.
Cryptomatte

Builds a matte from cryptomatte layers.
Cryptomatte Decode

Decodes a cyrptomatte into coverage and ID.
Cryptomatte Encode

Encodes a coverage and object hash into a cryptomatte layer.
Denoise AI

Denoises an input layer.
Denoise TVD

Removes white noise from an image.
Derivative

Computes the derivative of the source layer along the x- and y-axis.
Dilate Erode

Dilates or erodes a layer.
Distort

Distorts an input layer.
Dot Product

Performs dot product between two layers.
Edge Detect

Detects edges in the input image.
Edge Detect by Contour

Detects varying-width silhouette lines.
Edge Detect by Depth

Detects varying-width self-occluding silhouettes.
Edge Detect by Normal

Detects varying-width crease-lines.
Eikonal

Computes distances by solving the Eikonal equation.
Equalize

Equalizes colors by stretching or shifting their range.
Error

Generates a message, warning, or error.
Extrapolate Boundaries

Fills empty areas of an image using colors at the edges of non-empty areas.
Feather

Smooths out sharp changes in contrast.
File

Loads an image or video from disk.
Fill

Fills a layer with a constant value.
Flip

Flips a layer horizontally, vertically, or diagonally.
Font

Rasterizes text onto a layer from Type 1, TrueType, and OpenType fonts.
Fractal Noise

Generates fractal noise.
Fractal Noise 3D

Generates fractal noise from 3D locations.
Function

Applies a mathematical function to a layer
Gamma

Applies gamma correction to a layer.
Geometry to Layer

Converts a 2D volume into a layer.
Glow

Adds glow to an image based on its luminance.
HSV Adjust

Converts between RGB and HSV color spaces, or modifies HSV.
Height to Ambient Occlusion

Imagines a sphere for each pixel and determines how occluded that sphere is based on its surroundings.
Height to Normal

Converts a height layer to a normal layer.
Hex Tile

Randomly tiles texture.
Histogram

Builds a histogram from a layer.
ID to Mask

Creates a mask from an ID layer based on filtering parameters.
ID to Mono

Converts an ID layer into a mono layer.
ID to RGB

Converts an ID layer into an RGB layer.
ID to SDF

Computes a Signed Distance Field from changes in ID values.
Illegal Pixel

Detects and then fixes or highlights illegal pixels in images.
Input

Fetches the input to a subnetwork.
Invert

Inverts a layer.
Invoke Block

Runs a block using inputs plugged into this node.
Julia Fractal

Computes the Julia set to create a fractal.
Kuwahara Filter

Applies the Kuwahara filter, which creates painterly effects.
Layer

Generates a layer.
Layer Attribute Create

Adds or edits user-defined metadata on a layer.
Layer Properties

Edits basic layer metadata.
Layer to Geometry

Converts a layer into a 2D volume.
Light

Lights a layer given a light direction and normals.
Match Camera

Transforms a layer to match a reference camera.
Median

Applies a median filter to an image.
Mirror

Mirrors an image based on an arbitrary number of planes.
Mono

Converts a layer to mono.
Mono to ID

Converts a mono layer into an ID layer.
Mono to RGB

Converts a mono layer into an RGB layer.
Mono to RGBA

Converts a mono layer into an RGBA layer.
Mono to SDF

Computes a signed distance field from an iso-level of a mono layer.
Null

Passes inputs to the outputs.
OCIO Transform

Converts color spaces using OCIO transforms.
ONNX Inference

Applies inference from an ONNX Machine Learning model.
OpenCL

Executes an OpenCL kernel on layers.
Output

Collects the outputs of a subnetwork.
Polar to UV

Converts polar coordinate pixels to Cartesian pixels.
Position Map

Generates a Position Map.
Prefix Sum

Computes the prefix sum of a layer.
Premultiply

Premultiplies an RGBA layer.
Preview Material

Applies the preview material to geometry.
Project on Layer

Projects a layer onto a target layer.
Quantize

Quantizes input data into discrete steps.
RGB to RGBA

Converts RBG layers to RGBA.
RGB to UV

Splits an RGB layer into UV and Mono layers.
RGBA to RGB

Converts RBGBA layers to RGB.
RGBA to UV

Splits an RGBA layer into two UV layers.
ROP Image

Writes the output of a COP network to disk.
Ramp

Generates linear and radial ramps.
Random Mono

Creates a Mono layer with random values.
Random RGB

Creates a Mono layer with random values.
Rasterize Geometry

Rasterizes geometry onto a layer.
Rasterize Layer

Rasterizes a layer onto another layer’s camera.
Rasterize Setup

Prepares geometry for the Rasterize Geometry COP.
Remap

Remaps a layer.
Resample

Performs image scaling by changing the width, height and pixel sizes.
SDF Adjust

Modifies the values for a Mono SDF layer.
SDF Blend

Combines two Mono SDF layers.
SDF Shape

Builds a 2D signed distance field of a selected shape.
SDF to Mono

Converts an SDF field to a Mono image layer.
SDF to RGB

Converts an SDF field to an RGB color layer.
SOP Import

Imports SOP Geometry into Copernicus.
Segment by Connectivity

Segment a layer into connected components.
Segment by Value

Segment a Mono layer into bands of similar value.
Sequence Blend

Blends multiple image inputs by a blend factor.
Slap Comp Import

Import live layers from the Solaris Viewport.
Slope Direction

Converts a height layer into a direction layer.
Smooth Fill

Smoothly fills a region of a layer.
Stamp Points

Stamps layers from point positions.
Statistics

Outputs the average, minimum and maximum values of the input layer
Statistics by ID

Compute statistics for each ID island.
Streak Blur

Streaks an image, adding a motion blur effect.
Subnetwork

Used to organize a collection of COPs into one node.
Switch

Selects an input layer.
Switch If Wired

Selects an input based on what is connected.
Switch by Type

Selects an output layer by the type of the inputs.
Tile Pattern

Generates rectangular tiles for texture patterns.
Transform 2D

Transforms a layer in 2D.
Transform 3D

Transforms a layer in 3D.
UV Map

Generates a UV Map.
UV Map by ID

Creates a UV Map for each connected ID island.
UV Sample

Samples an input layer using a UV layer.
UV Transform

Transforms the values of a UV layer in 2d space.
UV to Polar

Converts Cartesian coordinate pixels to polar coordinate pixels.
UV to RGB

Joins an UV and Mono layer into an RGB layer.
UV to RGBA

Joins two UV layers into an RGBA layer.
Vector Transform

Transforms values of an RGB layer in 3d space.
Wipe

Performs a wipe transition between two images.
Worley Noise

Generates Worley noise.
Worley Noise 3D

Generates Worley noise from 3d locations.
Wrangle

Runs a VEX snippet to modify layer values.
Z Composite

Composites two layers by depth.