AI keying vs Primatte Keyer: neural unmixing compared to Boris FX's professional chroma keyer

Primatte Keyer has been a film and television staple for over two decades. Boris FX sells it at $295 as a standalone plugin, or as part of the larger Continuum suite. It works. Professionals trust it.

AI chroma keying is a different approach entirely. Instead of modeling a color volume and letting you sculpt it by hand, neural networks learn what foreground and background look like at the pixel level. CorridorKey, the open-source AI keyer released by Corridor Digital, introduced "neural unmixing" to the VFX community in 2024. EZ-CorridorKey (the most-forked version on GitHub) builds on that foundation.

These are not the same tool in different packaging. They solve chroma keying with fundamentally different methods, and each has genuine advantages.

What is Primatte Keyer?

Primatte uses a polyhedric color suppression algorithm. That is a fancy way of saying it builds a 3D geometric shape around your green screen color in RGB space, then decides what is foreground, background, or semi-transparent based on how close each pixel sits to that shape.

The auto-analyze feature handles clean, well-lit footage with one click. For problem shots, you get manual tools: foreground/background cleanup brushes, spill sponge, matte choker, light wrap, edge color correction. Every parameter is exposed. If you know what you are doing, you can pull a clean key from almost anything.

Primatte runs as a native plugin inside After Effects, DaVinci Resolve, Premiere Pro, Avid Media Composer, Final Cut Pro, and Nuke. Real-time playback on modern hardware. No round-tripping.

Boris FX sells it at $295 standalone or as part of Continuum ($1,995). Either way, you get professional support, regular updates, and a tool with decades of production history behind it.

What is AI keying?

AI keying replaces the manual color-volume approach with a trained neural network. The model used in CorridorKey and EZ-CorridorKey performs "neural unmixing," which means it predicts both the alpha matte and the clean foreground color for every pixel.

Traditional keyers give you a matte. The foreground pixels near green edges still carry green contamination that you handle with spill suppression. AI keying attempts to recover what the foreground pixel actually looked like before the green screen light hit it. The output is a clean foreground layer, not just a cutout.

The tradeoff: AI keying is batch-processed. You feed frames in, the model processes them, you get results back. It is not a real-time plugin inside your NLE. It is an external tool in your pipeline.

For a deeper explanation of how neural unmixing works, see our guide to AI chroma keying.

Feature comparison

Where Primatte wins

Real-time native plugin

Primatte runs inside your editor. Drop it on a clip, see the result immediately. Adjust while the timeline plays back. No exporting frames, no waiting for batch jobs, no importing results. For editors on deadline, this workflow advantage is hard to overstate.

Deep manual control

When auto-analyze does not get it right, Primatte gives you the tools to fix it by hand. Foreground and background cleanup brushes let you paint corrections directly on the image. The spill sponge removes green bounce from skin and clothing. Matte choker tightens edges. Light wrap blends the foreground into the new background.

An experienced compositor can solve nearly any keying problem with these tools. That flexibility does not exist in AI keying, where you get what the model gives you.

Runs everywhere

Primatte works in After Effects, DaVinci Resolve, Premiere Pro, Avid Media Composer, Final Cut Pro, and Nuke. Whatever your team uses, Primatte fits into it as a native plugin. AI keying currently requires a separate processing step outside the NLE.

Proven production history

Studios have shipped feature films, broadcast shows, and commercials with Primatte for over 20 years. It is a known quantity. When a client asks what tools you used, "Boris FX Primatte" is an answer that nobody questions.

Professional support

A $295 license comes with support from Boris FX. Bug reports get addressed. Documentation is maintained. Training resources exist. Open-source AI keying tools rely on community support, which can be excellent or nonexistent depending on the project.

Where AI keying wins

Free and source-available

CorridorKey is open source. EZ-CorridorKey is source-available and free to use. The entire cost is your time setting it up. For independent filmmakers, students, and hobbyists, $295 for Primatte is a real barrier. AI keying removes that barrier completely.

Hair and fine detail without manual work

This is where AI keying genuinely outperforms traditional methods on certain footage. Wispy hair, fur, loose fabric, and other semi-transparent edge detail often requires significant manual work in Primatte. You might spend 20 minutes per shot tweaking the matte choker, adjusting edge softness, and painting foreground corrections.

The neural network handles these details automatically. It has seen thousands of examples of hair against green screens during training. On footage where hair is the main challenge, AI keying often produces a better result with zero manual effort.

Motion blur

Fast movement creates motion blur that mixes foreground and background colors. Traditional keyers treat those blurred pixels as partially transparent, which is technically correct but visually messy. The edges look harsh or noisy.

AI keying handles motion blur more naturally because the network learned from training data that included blurred frames. The transition between foreground and background stays smooth even on fast-moving subjects.

Clean foreground color recovery

Primatte gives you a matte (which pixels are foreground, which are background, which are in between). The foreground pixels themselves still carry color contamination from the green screen. You then use spill suppression to remove the green tint, which is an approximation.

AI keying predicts what the foreground pixel would have looked like without any green screen influence. The result is a cleaner foreground, especially on reflective surfaces, translucent materials, and edges where green bounce is strongest.

No per-shot parameter tweaking

Primatte's auto-analyze is good. But on problem footage (uneven lighting, wrinkled backdrop, shadows on the green screen), you end up adjusting parameters shot by shot. AI keying processes every frame the same way. You do not adjust anything. For a project with 200 green screen shots of varying quality, the time savings add up.

The real question

This is not a "which is better" comparison. These tools solve different problems in different ways.

Primatte is a production workhorse. If your team has budget, works inside an NLE, and needs real-time keying with the ability to fix any problem shot by hand, Primatte earns its $295. It fits into existing pipelines. It works on deadline. It is a solved problem.

AI keying is a specialty tool. It excels on specific footage where traditional keyers struggle: hair-heavy shots, motion blur, reflective costumes, translucent materials. It costs nothing. But it requires batch processing, lives outside your NLE, and gives you limited control when the result is not perfect.

Many VFX artists will end up using both. Primatte handles 90% of their green screen work inside the timeline. For the remaining 10% where hair or motion blur defeats traditional keying, they run those specific shots through AI keying and composite the result.

That is not a compromise. That is using the right tool for each job.

FAQ

Is AI keying a replacement for Primatte?

No. AI keying and Primatte solve chroma keying with different methods for different situations. Primatte is a real-time NLE plugin with deep manual controls, built for production teams who need keying inside their timeline. AI keying is a batch processing tool that excels on specific problem footage (hair, motion blur, translucent materials) but lacks real-time preview and manual correction tools. Most professionals will use a traditional keyer like Primatte as their primary tool and reach for AI keying on the shots where traditional methods fall short.

Is EZ-CorridorKey free?

Yes. EZ-CorridorKey is source-available and free to use, with over 4,000 stars on GitHub. It is a fork of Corridor Digital's CorridorKey, the AI chroma keyer that Corridor Digital released as open source in 2024. Version 2.0 added blue screen support alongside green screen keying. It is a work in progress, not a finished commercial product. Download it from Gumroad or build from source.

Can I use AI keying inside DaVinci Resolve or After Effects?

Not directly. AI keying tools like EZ-CorridorKey run as external batch processors. You export your green screen frames, process them through the AI model, then import the keyed result back into your NLE. Primatte, by contrast, runs natively inside Resolve, After Effects, Premiere, Avid, FCP, and Nuke with no round-tripping required.

Which tool handles hair better?

It depends on the footage and how much time you have. On well-lit footage with clean green screen separation, an experienced Primatte user can pull excellent hair detail with manual tuning. On difficult footage with uneven lighting or fast movement, AI keying often produces cleaner hair edges with no manual work at all. If you regularly shoot interviews or dialogue scenes with actors who have fine or curly hair, AI keying is worth testing on a few shots to see how it compares to your current keying workflow.

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EZ-CorridorKey is developed by Ed Zisk at EZSCAPE, creator of DITHERON, CRTified, and Cucolori.