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AI図鑑

顔認識

二つの顔が同一人物かを判定する

視覚理解中級 #16
入力画像表

本ページの本文は英語で提供されています。タイトルと導入は日本語化されています。

この能力とは何か

Takes one or two face images and outputs an identity decision: verification answers whether the two are the same person, while identification asks who in a gallery a face matches. Faces are first aligned and encoded into feature vectors, then compared by distance. Unlike classification the class set is not fixed; the comparison target comes from a dynamic gallery.

技術的にどう実現するか

The pipeline typically detects a face, aligns it by keypoints, and extracts a feature vector with a deep network trained by metric learning to pull the same person together and push others apart. Early systems relied on hand-crafted features; deep metric learning around 2014 pushed accuracy past the practical threshold. Liveness detection, which separates a live person from a photo or a mask, is an indispensable part of any deployment.

代表的な製品

1

関連する組織

代表的な用途

  • Access control and ID verification
  • Automatic people grouping in photo albums
  • Identity confirmation for remote account opening
  • Video search and person tracking

どう評価するか

1:1 verification accuracy
Correct same-or-different decisions
TAR@FAR
True accept rate at a fixed false accept rate
Identification mAP
Ranking quality when searching a gallery

限界と難しさ

  • Large pose differences, age gaps and harsh lighting push the same person apart in feature space
  • Uneven training data produces systematic bias across skin tones and genders
  • Photos, replayed video and realistic masks can fool the system, so liveness detection is required, not optional

背景にある概念