Overview

Luma Key is an effect block commonly used to remove black or white backgrounds from images or videos.

The effect generates a greyscale luma matte based on the applied layer's luminosity. This luma matte renders white for pixels within the specified luma range and black for pixels outside of the range. The matte can then be used as a luma mask on the layer, making the matching pixels transparent.

You can find Luma Key in the Block Browser under the "Color" category. It's often used for removing black or white backgrounds from layers. This block operates very similarly to Chroma Key.

Controls

Min/Max

These two properties work in tandem to set the luminosity range you’d like to keep visible. A value of 0 is no luminosity (black) and a value of 1 is full luminosity (white).

Smoothing

Smoothing makes the matte edge more organic and similar to what your eye sees on an image. It makes pixels semi-transparent that are similar to the selected luminosity range. Higher smoothing values include more pixels in the matte, creating a softer edge. A value of 0 means no smoothing is applied.

Output

Output controls what the block renders. There are two options:

• Matte: Renders the greyscale luma matte generated by the block. Use this setting to inspect the underlying matte or use the layer as a cross-layer luma mask.

• Final: Renders the layer with the matte applied as a mask on itself. Use this mode to immediately remove pixels without needing to create or manage cross-layer mask connections.