Corridor Key Green Screen Keying for Video

AI green screen keying that preserves hair, motion blur, and transparent edges.

Upload your green screen video, and Corridor Key separates the foreground from the background at the pixel level. Instead of a harsh cutout, you get a clean alpha channel that keeps semi-transparent details intact. The workflow outputs both a composite preview and a standalone alpha matte video.

No prompt needed. Upload, adjust your keying settings, run it.

How do you key green screen footage with Corridor Key?

Upload a green screen video and Corridor Key's neural network separates foreground from background for every pixel. It predicts true foreground color and a clean alpha channel, preserving hair, motion blur, and transparent edges that standard keyers destroy.

Screen Color Set to green by default. If you shot on a blue screen, switch this to blue.

Threshold Controls how aggressively the keyer separates foreground from background. Default is 0.15. Want a tighter key with less fringe? Lower it toward 0.05. Getting holes in your subject? Raise it toward 0.3. Start at the default and adjust from there.

Softness Affects the transition between foreground and background at edges. Default is 0.1. Want harder edges for graphic looks? Go lower. Want softer blending for natural composites? Push it toward 0.2 to 0.3.

Erode Shrinks the alpha matte inward. Default is 2 pixels. If green fringe still shows at the edges, bump this up to 3 or 4. Too high and you start eating into your subject.

Blur Smooths the alpha matte edges. Default is 5. Higher values give softer transitions. Lower values keep edge detail sharper. Play with it alongside erode to find the right balance.

Despill Strength Removes green color contamination from your subject. Default is 1 (full strength). If your subject looks too neutralized or skin tones shift, try 0.5 to 0.7.

Refiner Scale Controls the edge refinement pass. Default is 1. Higher values put more work into cleaning up fine edge detail.

Auto Despeckle On by default. Removes small floating artifacts and noise in the alpha channel. If you need every tiny detail preserved, turn it off. For most footage, leave it on.

Resolution Set through custom width and height on the video loader. Defaults handle up to 1920x1080. For 4K plates, set 3840x2160.

What is Corridor Key good for?

Corridor Key solves the hardest part of green screen compositing: getting a clean key from footage with hair, smoke, motion blur, or transparent objects. It replaces the hours spent building complex edge mattes and manual roto work that traditional keyers require.

This workflow is built for video. Upload your green screen clip, and it processes every frame. You get a composite preview video and a separate alpha matte video, ready to bring into your editing timeline or compositing software.

Product videos where talent handles transparent packaging. Music videos with flowing hair and fabric. Corporate talking heads shot in small studios with uneven green screens. Interview footage where the subject moves and creates motion blur. These are the situations where traditional keyers fall apart and you end up rotoscoping by hand.

If your footage has a clean, well-lit green screen and a subject with hard edges, a standard keyer will work fine. Corridor Key earns its keep on the difficult shots.

Built by Niko Pueringer and the Corridor Digital team. Open-source neural network trained on synthetic data to handle the cases traditional keyers cannot.

FAQ

What resolution does Corridor Key support? The model scales to handle footage up to 4K. Set your target resolution in the video loader node. For best results on high-res footage, you need enough VRAM to process at full resolution. 1080p runs well on most setups.

Does Corridor Key work on blue screen footage? Yes. Change the screen color setting from green to blue. The keying pipeline works the same way. Green screen footage tends to produce slightly cleaner results because the model was primarily trained on green backgrounds.

Can I use the alpha matte in other software? Yes. The workflow outputs a separate alpha matte video. Import it into DaVinci Resolve, After Effects, Nuke, or any compositing tool as a luma matte. The composite preview is for quick checks inside the workflow.

How do I fix green spill on skin tones with Corridor Key? Adjust despill strength. Full strength (1.0) removes all green contamination but can shift skin tones. Try 0.5 to 0.8 for a balance between spill removal and natural color. If edges still show green, increase the erode setting by 1 or 2 pixels.

How to run Corridor Key online? You can run Corridor Key online through Floyo. No installation, no setup. Open the workflow in your browser, upload your inputs, and hit run. Free to try.

Credits & Acknowledgements

CorridorKey was created by Niko Pueringer and the Corridor Crew team. Their video "It Took Me 30 Years to Solve this VFX Problem" walks through how the AI-powered keyer works and why it represents a major leap over traditional chroma keying methods. The ComfyUI integration used in this workflow comes from ComfyUI-CorridorKeyWrapper by pixelworldai, which packages the CorridorKey neural network into a set of easy-to-use ComfyUI nodes for model loading, green screen inference, alpha hint generation, and compositing. Huge thanks to both for making this technology accessible to the community.