Chroma Key

The Chroma Key operator removes points by colour, the same way a green screen is keyed in video. Each point's colour is converted to HSV and points falling inside the key are discarded. It can be used to strip a backdrop or coloured props from a scene, or with Invert enabled to isolate them.

Operator Properties

• Target Hue: the centre of the key on the colour wheel, in degrees. The default of 140° targets green.
• Hue Width: the span of hues around the target that are keyed, in degrees.
• Minimum Saturation: points less saturated than this are never keyed, which protects greys and skin tones.
• Minimum Value: points darker than this are never keyed, which protects shadows.
• Invert: keep only the points inside the key and remove everything else.
• Backend: run the operator on the CPU or with CUDA.