ANR Despill

Overview

Despill removes the green or blue that a screen spills onto the foreground: on skin, hair, clothes and edges. For green, each pixel's green is limited by its red and blue; the excess is the spill and is taken out, while neutral greys and whites are left alone. Blue works the same way, and Custom handles a screen colour that is not a pure green or blue.

Taking spill out also takes out brightness, which can leave edges dull or dark. Luminance Recovery puts that brightness back, tinted by Replacement Color. Spill Balance sets how strong the limit is, Spill Threshold leaves a little of the screen colour in, and Soft Edge Restriction limits the work to the soft edges of the matte. View: Spill Matte shows exactly what is removed.

It changes colour only: it does not build, erode or soften the key. Use it with your keyer, before ANR Edge Color and ANR Light Wrap.

Inputs

1. Sourcerequired

   The keyed element, premultiplied, with its matte in alpha. Pixels with no alpha are left as they are.

2. Maskoptional

   Limits where spill is removed, by its alpha. Use it to protect wanted green or blue, such as a green shirt.

Output. The Source with the spill removed and its alpha unchanged. View: Spill Matte shows the removed spill instead, as a greyscale image.

Quick start

1. Add ANR Despill after your key and connect the keyed element to Source.
2. Set Spill Color to Green or Blue. For another screen colour, choose Custom and pick the screen's colour from the plate into Custom Spill Color.
3. Set View to Spill Matte to see what is removed, then go back to Result.
4. Adjust Spill Balance: lower for a gentler despill, higher for a stronger one.
5. If edges or skin look dull or dark, raise Luminance Recovery; keep Replacement Color white for a neutral result.
6. Protect wanted green or blue with the Mask input, or raise Spill Threshold to leave a little of it.

The panel

The node's panel as Nuke shows it, with the values of a new node. Click any control to see what it does; tabs and sections work as in Nuke.

All controls

Tips

• To despill only hair and other soft edges, raise Soft Edge Restriction toward 1: the solid parts of the element are then left alone.
• Highlight Protection keeps bright highlights, such as a specular kick or a white shirt, from being changed.
• Tint Replacement Color toward the new background's colour when the edges should pick up that environment's light. White adds no new colour.
• Order in the comp: key, Despill, ANR Edge Color, ANR Light Wrap, then the Merge.

Good to know

• Only pixels with some alpha are treated. If nothing changes at all, check the Source's alpha.
• A premultiplied element can go straight in: the node unpremultiplies and premultiplies again by itself.
• Runs on the CPU: no GPU and no AI model needed.

Works with

ANR Edge ColorGives the soft edges of a keyed or rotoed element the colour of the background behind them, so they blend in, without touching the alpha.ANR Light WrapWraps the background's light softly around the edges of a keyed or CG element, so it sits in the plate instead of looking cut out.