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AI図鑑

姿勢推定とキーポイント

関節点を求め、骨格を復元する

視覚理解中級 #14
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 an image or video and outputs coordinates for a set of keypoints — shoulders, elbows, wrists, hips, knees, ankles — which join into a skeleton. It adds geometric structure on top of detection and returns coordinate sequences rather than classes. It works both on a single person and on many people, grouping points per individual.

技術的にどう実現するか

Two paradigms dominate: top-down detects each person first and regresses keypoints inside the box, accurate but slower as the crowd grows; bottom-up predicts all joints over the image at once and assembles points into individuals using part-affinity fields, with speed largely independent of headcount. Heatmap regression was long the standard, and direct coordinate regression with Transformer backbones has since matured.

代表的な製品

4

関連する組織

代表的な用途

  • Fitness and sports motion analysis
  • Human–computer interaction and gesture control
  • Motion capture and animation driving
  • Hand and face tracking

どう評価するか

PCK
Share of keypoints falling within a radius of the truth
OKS / keypoint mAP
Detection average precision weighted by joint visibility
MPJPE
Mean joint position error in 3D pose, in millimetres

限界と難しさ

  • Occlusion and crops drop keypoints, yet the model still fills in a plausible but wrong location
  • Extreme poses — handstands, curled-up bodies — fall outside training and amplify error
  • With mutual occlusion, limbs are stitched onto the wrong person

背景にある概念