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Mask From Image

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Mask

Extracts a grayscale mask from any channel of an image: alpha, red, green, blue, or luminance.

Mask From Image converts an image channel into a single-channel mask. Choose alpha, any individual RGB channel, or luminance as the source. The threshold binarizes the result (hard black/white), and feather softens the edges.

This is the primary way to create masks from existing image data. Extract the alpha for silhouette masks, or use luminance to create brightness-based selections.

Parameters

Section titled “Parameters”

Pins

ImageImage
InputRequired
AlphaMask
Output

Mask

ChannelChoice
Default: Alpha

Which channel to extract as the mask

  • AlphaUse the transparency channel — bright where opaque, dark where transparent.
  • RedUse the red channel as the mask source.
  • GreenUse the green channel as the mask source.
  • BlueUse the blue channel as the mask source.
  • LuminanceUse perceived brightness — the most natural representation of "light vs dark."
ThresholdInteger
Default: 0 Range: 0–255

Pixels at/above this value become opaque mask. 0 keeps grayscale

Feather (px)Number
Default: 0.0 Range: 0.0–100.0

Gaussian feather radius applied after threshold

InvertToggle
Default: false

Invert the resulting mask

Usage Tips

Section titled “Usage Tips”
  • Extract from Alpha to get a mask of the image’s transparent areas.
  • Use Luminance to create a brightness-based mask where bright areas become white and dark areas become black.
  • Combine threshold with feather for semi-soft selections.
  • Enable Invert to flip the extracted mask without a separate Invert node.
  • Threshold at 0 keeps the full grayscale result; raise it to create a hard binary mask.
Section titled “Related Nodes”