DEV Community

Denys Kramar
Denys Kramar

Posted on

Twins Finder - Searching for people in photos and comparing faces

Image description
I Built a Face Recognition SDK
Had an idea for an app that finds facial similarities in group selfies. Seemed simple. Wasn't.

What I Looked For First
Cloud APIs (AWS, Google): Work fine, but uploading user photos to Amazon felt wrong. Plus expensive.
Open Source: Either academic experiments with poor accuracy or server-focused with massive dependencies.
Commercial SDKs: $1k+ licenses designed for enterprise.
So I Built PerchEye SDK

Core requirements:

  • Completely offline
  • Cross-platform (Android, iOS, Flutter, React Native)
  • Actually fast on mobile devices
  • Privacy-first design

Performance achieved:

  • Face detection: ~50-100ms
  • Hash generation: ~150ms
  • Model size: ~15MB
  • Memory usage: ~75MB
  • Accuracy: >95% for clear faces

Then Built Twins Finder App
Simple workflow:

  • Take group selfie
  • Detect faces
  • Generate mathematical hashes (no actual face storage)
  • Compare similarities
  • Show results

Everything stays on-device. Only math representations stored, never face images.

Twins Finder - Download
PerchEye SDK - GitHub

Open Source
Released PerchEye for free because this tech shouldn't cost enterprise money.
Anyone else working on mobile computer vision? What challenges have you hit?

Top comments (0)