Keypoints

Specific locations used to represent visual features or meaningful landmarks on an object or body.

In annotation, a keypoint may identify a joint, fingertip or tool tip. Computer vision also uses automatically detected feature points. A review rubric should specify which kind is intended, how visibility is recorded and whether an obscured point may be inferred or must remain unknown.

In practice

A hand pose annotation distinguishes a visible fingertip from one hidden behind the manipulated object.