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PIK Keyer

PIK Keyer · screenshot coming soon

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What this node does

PIK Keyer is a professional green/blue-screen keyer modeled on the classic IBK (image-based keyer) / Primatte approach. Instead of judging each pixel only by a single screen color, it can compare your footage against a clean plate (the empty screen) and use garbage masks to force areas fully in or fully out. It also has built-in despill and a “replace” stage to fill the removed spill with a chosen color or the background. Input and output are COMFYTV_VIDEO. It has a ▶ Run. There are two working modes, chosen automatically: if you wire any of the side inputs (clean plate, in/out mask, or a background video) it runs the full clean-plate keyer; if you leave them all empty it falls back to a fast, live-previewable single-image key using just the screen settings.

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When to use it

  • The screen is unevenly lit or has shadows/wrinkles a simple key can’t handle — a clean plate fixes it.
  • You need to hand-hold problem areas (a green prop to keep, a hole to punch) with garbage masks.
  • You want to composite straight onto a background clip in one node.

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Parameters

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screen

Which backdrop to key: green (default), blue, or pick to use your own pick_color.

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pick_color

The custom screen color when screen is pick. Hex, default #00FF00.

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red_weight / blue_green_weight

Balance controls for how the screen channel is separated from the rest of the image. Both range -1.0–2.0, default 0.5. Adjust to firm up the matte without eating the subject.

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alpha_bias / despill_bias

Neutral-color references (hex, default #808080 gray) that bias how alpha is generated and how despill is applied. Set these toward your subject’s neutral tone to reduce spill artifacts.

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use_alpha_bias

When on (default), the alpha bias also drives despill. Turn off to decouple the two.

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screen_subtraction

When on (default), subtracts the screen contribution from the image for a cleaner core matte.

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clip_black / clip_white

The matte’s black and white clip points. clip_black (default 0.0) forces near-transparent values fully transparent; clip_white (default 1.0) forces near-opaque values fully opaque. Both range 0.0–1.0. Pull them in slightly to crush noise in the matte.

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replace_mode / replace_color

How to fill where spill was removed. replace_mode is none, source, hard, or soft (default soft). replace_color (hex, default #808080) is the fill color used by the hard/soft modes.

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output

alpha (default) for real transparency, matte for a grayscale mask, premult for premultiplied RGB, or composite to render straight over the background. (alpha needs the VP9 encoder — use matte if it errors.)

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Side inputs (optional)

  • video — the plate to key.
  • clean_plate_video / clean_plate — the empty screen as a video or a still image; enables the full IBK key.
  • in_mask — a garbage mask marking areas to force fully opaque (keep).
  • out_mask — a garbage mask marking areas to force fully transparent (remove).
  • bg_video — a background clip used when output is composite.

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Outputs

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Tips

  • Wiring any side input switches this node into full-render mode (a ▶ Run pass). With no side inputs it stays a fast, previewable single-image key.
  • A clean plate is the single biggest quality win for uneven screens — shoot one whenever you can.
  • Use in_mask to protect green props and out_mask to knock out reflections or rig holes.
  • To interoperate with native ComfyUI nodes, insert a Bridge. See bridges.md.
  • Chroma Key — simpler, single-color key when you don’t need clean plates or masks.
  • Keyer — luma/chroma keyer with two-sided tolerance/softness.
  • Despill — standalone spill cleanup.
  • Key Mix — composite a foreground over a background with a matte.