Enable it in Synology Photos and then let it re-index or generate previews:
- Go to Account icon > Settings > Personal (Personal Space) or Shared Space > Indexing > Re-index.
- Open a photo, click More in the upper-right corner, then generate preview. This activates AI-powered recognition.
- You can also manually tag faces from More > tag faces.
- In People albums, facial recognition lets you name, hide, or merge detected faces.
If faces are not grouping:
- Check permissions or storage space; inability to tag people can be caused by insufficient permissions or space.
- Note that manually tagged faces are not used to train AI-powered recognition.
- New previews may create different groupings in People, Subjects, and Similar Items.
- Re-indexing can re-run recognition and may change existing groupings.
Sources used: [3], [4], [12]