Effects
pMix.studio supports per-source video effects that are applied before compositing. These can be configured on individual input sources or on individual layers within composite scenes.
Chroma key (green/blue screen)
Chroma key removes a specific color from the video, making that area transparent. This is commonly used with green or blue screen backdrops to composite a presenter over another source.
Settings
| Setting | Range | Description |
|---|---|---|
| Key color | RGB | The color to remove (green or blue presets available) |
| Similarity | 0.0–1.0 | How close a pixel must be to the key color to be removed. Higher values remove more. Default: 0.15 |
| Smoothness | 0.0–1.0 | Edge softness between keyed and non-keyed areas. Default: 0.08 |
| Spill reduction | 0.0–1.0 | Reduces color spill from the backdrop onto the subject. Default: 0.5 |
Presets
- Green screen — Key color: green (0, 1, 0)
- Blue screen — Key color: blue (0, 0, 1)
Both presets use similarity 0.15, smoothness 0.08, and spill reduction 0.5 as starting points. Adjust these values based on your lighting conditions.
Tips
- Even lighting is critical — shadows and hotspots on the backdrop will create areas that don’t key cleanly
- Increase similarity if parts of the backdrop are not being removed
- Increase smoothness if edges look jagged or harsh
- Increase spill reduction if the subject has a green/blue tint from the backdrop
AI background removal
Background removal uses on-device AI person segmentation to isolate people from their background — no physical green screen needed.
Quality levels
| Level | Mask resolution | Processing time | Use case |
|---|---|---|---|
| Fast | 64x64 | ~2–3 ms | Best performance, suitable for most productions |
| Balanced | 192x192 | ~15 ms | Higher-quality edges, use when performance allows |
When to use
- No green screen available — Background removal works with any backdrop
- Mobile/field productions — No need to set up and light a green screen
- Casual content — Quick way to composite a presenter over slides or graphics
Limitations
- Works best with a single person in frame
- Fast-moving subjects may show edge artifacts
- Performance depends on iPad model — monitor frame rates when using background removal on multiple sources simultaneously