Keying replaces the green behind your guests with the backdrop. Do it at the venue, under the event lighting, with someone standing in the guest spot.
Calibrate it
- Open admin, then Green screen. You see the live result over a test backdrop. Tap Test background on over the preview to see the plain camera instead, and again to bring the backdrop back.
- Tap Pick from the screen, then tap a typical area of the green screen: not the brightest or the darkest spot. The circle next to Key colour updates.
- Turn on Show matte. The preview turns black and white: white is kept, black is replaced by the backdrop. You want the person solid white and the screen solid black.
- Move the three sliders until the matte is clean.
- Turn Show matte off and check the result with a real backdrop.
Changes save when you lift your finger. To fine-tune the colour by hand, tap the Key colour circle, drag on the colour wheel and brightness bar, then tap Done (or Cancel).
Set the camera's zoom, brightness and exposure first, in Camera, because they change what the key sees.
The three sliders
- Similarity (30% by default): how much green counts as the screen. Higher removes more.
- Edge softness (20% by default): softens hair and outlines. Higher blends edges more.
- Spill removal (50% by default): takes the green tint off people.
What to move when something looks wrong
- Patches of green still showing: raise Similarity, or pick the key colour again from a more typical area.
- Parts of the person disappearing: lower Similarity.
- Hard, jagged edges: raise Edge softness a little.
- A blurry halo or see-through edges: lower Edge softness.
- A green fringe on hair, or green on skin and clothes: raise Spill removal.
- Skin or clothes look grey or washed out: lower Spill removal.
- Nothing looks right: tap Reset to defaults and start again. The round button next to Key colour resets just the colour.
If the sliders can't get a clean key, the problem is usually the lighting. Light the screen more evenly and move guests further forward. See Setting up the booth.
Tune it from the booth
On the booth's Backdrop tab, Green screen opens the same controls over the live booth, without the colour wheel: Pick, Show matte, the three sliders and Reset to defaults. They save as admin's do, so you see exactly what guests see while you tune. On White label you can hide this button: Booth defaults > Guests can change > Green screen in the booth.
No green screen? Use on-device AI
At the top of Green screen, Background offers Green screen or No green screen (on-device AI). With AI, the app finds the people in the picture itself, on the device. Nothing is sent anywhere.
- The key colour, Similarity and Spill removal are hidden. Edge softness softens the edge around people, and Show matte shows the people the app found.
- It works best with people standing still against a plain, evenly lit background. Hair, glasses, thin props and fast movement can show rough edges. A lit green screen always gives the best result.
- On a device that can't run it, the choice is dimmed with Not available on this device. If it stops working, the booth uses the green screen instead and tells you.
For every setting, see Green screen.