Luminance Threshold

The Luminance Threshold effect generates a matte by thresholding the luminance of an image. This works well with bitmap images that have many shades of colours. A pure vector image with flat colors could use a color override to isolate areas.

Thresholding is a method to segment or isolate certain zones in an image. This effect will isolate areas based on the image's luminance. Thresholding is used within the Bloom effect—see Bloom.

Luminance Threshold Properties

Parameter Description

Allows you to change the node's name.


Controls how much of the dark value to clamp off. A high value will keep only the bright areas of your image.

Soften Colours

Brings back the entire spectrum of luminance in areas defined by the threshold to avoid having only bright values.

Gamma Correction

Multiplies the gamma value to make the area brighter or darker. A value of 1 keeps the gamma the same as the original image. You can use the gamma modification on the whole image if you use a threshold of 0 for example.

Output Greyscale Matte

Allows you output an image in grey values to use in combination with a Blending or Cutter node elsewhere in the node structure.