record_detections replaces an image's faces and carried only the user's
confirmations onto the new ones, by box overlap above 0.5 IoU. Everything
else on the old faces was dropped: the suggestions the last grouping pass
made, and the people the user had said a face was not. On the reference
library that is 13,011 suggestions and 77 rejections beside 3,778
confirmations — a re-detection of it would have been correct by
FR-CULL-12's letter, since suggestions are derived data, and would have
handed back a People screen of strangers.
Now every old face is read before the delete — box, vector, assignment,
rejections — and matched to the new faces one-to-one, best pair first. A
pair qualifies when the boxes overlap at all and either the overlap alone
says so (IoU above 0.5, the old rule) or the embeddings do (cosine above
SAME_FACE_COSINE, 0.45, the reference library's P≈0.95 line). The
embedding route claims the box a low-resolution pass drew badly enough
that overlap alone would not; the vector is also what breaks the tie in a
group photograph, where two neighbouring faces overlap both new boxes.
Overlap is required on both routes, because the same vector elsewhere in
the frame — a mirror, a print on the wall — is not the same face and must
not take its name. Onto the matched face go the assignment as it was,
confirmed or suggested with its probability, and every rejection.
The merge's match_faces still matches by overlap alone across devices; it
is the same question and is not changed here.
dtourolle
2a4ac0ed3d