Makeup, turbans and dim lights: what trips up face matching

A wedding is a difficult place for face recognition. People look their least like their everyday selves, the lighting changes every hour, and half the best photos are taken while someone is mid-laugh and looking the other way.

Here's an honest look at what tends to get in the way at Indian weddings, and the small things that help.

Makeup and big outfits

Everyday makeup rarely makes much difference. Heavy bridal makeup changes more, particularly around the eyes and brows, but the underlying shape of a face stays the same. Face matching looks at that shape rather than at colour.

A safa, turban, dupatta or maang tikka generally isn't a problem either, as long as it isn't covering part of the face. A ghunghat that hides the face is a different matter: if a camera can't see a face, no software can match it.

Beards and glasses

Normal glasses are usually fine. Sunglasses at an outdoor haldi are harder, because they hide the eyes. If you've recently shaved off a beard or grown one, a selfie that shows how you looked at the event will do better than an old photo. That's a good reason to add your selfies with a little care rather than reusing a profile picture.

Dim halls and coloured lights

Sangeet nights are the toughest. Low light brings grain, and coloured stage lights change how skin looks from one second to the next. Faces at the back of a dark dance floor are often small and blurred as well.

Well-exposed photos from a good photographer give matching far more to work with than a dark phone photo. Photographers, a little fill flash on the floor helps your guests as much as it helps your portfolio.

Angles, the common one

Far more candid photos are taken from the side than straight on. This is why we ask for left and right profile selfies as well as a front-facing one. If you only do one extra thing, do this.

When a photo gets missed

No system finds everyone in every frame. Someone turned fully away or hidden behind a pillar will be missed, and that's normal. You have a few options:

• add your side-profile selfies if you skipped them
• browse the event's shared folders, where the big group photos often live
• ask the photographer, who can tag you by hand

Matching also keeps running. When new photos are uploaded, they're checked against your selfies, so your gallery can keep growing after the wedding is over.

What's worth doing

If you're a guest, add three clear selfies in daylight, without sunglasses. If you're the photographer, keep faces well exposed and upload your best selects first. Neither takes long, and both beat scrolling through 2,000 photos looking for yourself.