The tracking identifier of the face object.
- iOS 6.0+
- macOS 10.8+
- Mac Catalyst 13.0+
- tvOS 9.0+
- Core Image
Core Image provides a tracking identifier for faces it detects in a video stream, which you can use to identify when a
CIFace objects detected in one video frame is the same face detected in a previous video frame.
This identifier persists only as long as a face is in the frame and is not associated with a specific face. In other words, if a face moves out of the video frame and comes back into the frame later, another ID is assigned. (Core Image detects faces, but does not recognize specific faces.)