In short: AI cut-outs work best with a clear, well-lit subject that contrasts with the background. Blur and B&W pop are the most forgiving looks; full replacements need the best footage. Use a real green screen when edges must be perfect.
How AI finds the person
A segmentation model looks at each frame and estimates, for every pixel, how likely it is to belong to a person. VDOAPP uses Google's MediaPipe selfie segmenter, which is small enough to run many times per second in a browser. The output is a soft "mask" — white where the person is, black elsewhere, grey at uncertain edges — which is then used to treat the background differently from the subject.
Because the mask is soft, edges blend instead of looking cut out with scissors. The trade-off: very fine detail like individual hairs or the gap between fingers is simplified.
AI vs green screen
| AI segmentation | Green screen (chroma key) | |
|---|---|---|
| Setup | None | Backdrop, even lighting, distance from it |
| Works on old footage | Yes | Only if it was shot on green |
| Hair and fine edges | Simplified | Excellent when well lit |
| Objects held by the person | Sometimes lost | Kept (unless green) |
| Best for | Vlogs, webcam, interviews, social | Studio work, weather-map style composites |
VDOAPP has both: the AI cut-out in the AI tab and a chroma key with spill clean-up and edge controls in the PiP tab.
Filming for a clean cut-out
- Contrast. A dark jumper against a pale wall separates cleanly; a beige top against a beige wall doesn't.
- Light the person, not the room. A window or lamp in front of you (not behind) makes the edges clear.
- Keep the whole head in frame. The model is most confident when it can see head and shoulders.
- Avoid busy backgrounds with people in them. The model will cut them out too — it finds people, not just you.
Five background looks — and when to use each
- Blur. Imitates a wide-aperture lens. The most forgiving option: small edge errors disappear in the blur. Great for webcam talks and interviews in untidy rooms.
- B&W pop. The subject stays in colour and the world goes grey. Striking for dance, fashion and music videos; use sparingly — it's a statement.
- Spotlight. Dims everything but the subject, like a stage light. Useful for drawing attention to one person in a group shot.
- Colour. A flat, branded colour. Clean for explainers and product talk; the most demanding look, since every edge error shows against a flat field.
- Image. Your own picture behind the subject — a branded backdrop, an office, a location. Match the light direction and colour temperature of the new background to your footage or it will look pasted in.
Add a Neon outline for thumbnails, intros and energetic social clips — it turns the edge of the mask into a design element.
Step by step
- Add your clip and select it on the timeline.
- Open AI → AI effects · selected clip → Behind the subject.
- Choose a look. For Colour, pick the colour; for Image, choose a picture.
- Scrub through the clip to check tricky moments: hands moving fast, turning around, leaning out of frame.
- Export. The effect is rendered into every frame.
Fixing common problems
| Problem | Try |
|---|---|
| Edges flicker | Switch from Colour to Blur, or improve lighting next time |
| A chair or object stays visible | It's close to the person's outline; reframe or crop to exclude it |
| Hands disappear when moving fast | Motion blur confuses the mask; shoot at a higher frame rate or a faster shutter |
| A second person appears | The model finds all people — crop them out, or split the clip |
Frequently asked questions
Can I cut out a pet or a product?
For photos, yes — choose Any subject under What's the subject?. For video, the cut-out is trained on people.
Does it slow down the editor?
The model is small and runs on the graphics card where possible. On older devices, previews may drop frames, but the export is rendered frame by frame at full quality.
Is my video sent anywhere?
No. The model is downloaded once and runs in your browser.