Distance Key Node

Distance Key Node.

The Distance Key node determines a pixel’s alpha value based on the three-dimensional distance between the image pixel color and the key color in a 3D color space.

This key works well when trying to single out a specific color in a background (not necessarily green).

Inputs

Image

Standard image input.

Key Color

The color that is to be keyed.

Properties

Tolerance

A threshold what the node considers a match between the key color and the foreground pixel. The tolerance affects how close a pixel needs to be to the background pixel to be considered an absolute match.

Falloff

When the Falloff value is high, pixels that are close to the Key Color are more transparent than pixels that are not as close to the Key Color (but still considered close enough to be keyed). When the Falloff value is low, it does not matter how close the pixel color (Image) is to the Key Color, it is transparent.

Color Space

It is also possible to work with YCbCr color space, but only the Cb and Cr channels are taken into consideration for determining the distance between the foreground and background pixels.

RGB, YCC

Outputs

Image

The image with an alpha channel adjusted for the keyed selection

Matte

A black and white alpha mask of the key.