Also notes what building it taught the design: a split has to reject
before it confirms, or the next clustering pass undoes it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
FR-CULL-9 forbids thresholding a bare cosine anywhere in the subsystem,
so calibrate fits P(same person) per library and reports whether the fit
is trustworthy. Two details carry most of the weight.
The fit runs against a 200-bin histogram rather than a pair list: a
25,000-face library has ~3e8 pairs and no gradient descent is running
over that. And a fresh library has no valid calibration, because the
positives have to come from user confirmations or burst siblings --
bootstrapping them from high cosine would fit the calibration to the
belief it was supposed to test.
Clustering defends against the over-merging FR-CULL-10 warns about with
constraints rather than a better threshold: two faces in one photograph
never merge, and two groups confirmed as different people never merge.
Average link rather than single link, so one strong edge cannot weld two
families together.
Calibration is defined once, in dr-face, and dr-catalog re-exports it.
Two implementations of one probability model is exactly how a number
comes to mean the wrong thing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Ports the pipeline from the C++ reference in ../scene-actor-extraction
(MIT, same author). End to end on real portraits it separates identities
the way the reference's fitted calibration says it should: 0.596 between
distinct photographs of one person, 0.05 between different people, either
side of MBF's 0.267 boundary.
Three things are structural rather than incidental:
Aligned112 can only be built by align::warp, so Embedder::embed cannot be
handed an unaligned bounding-box crop. That mistake yields 512 plausible
unit-norm numbers and no error, so the type system refuses it instead.
Embedding carries its ModelId and cosine() returns None across models,
because a cross-model similarity is the one mistake that produces
plausible garbage rather than a failure.
The model-free half -- alignment, embedding arithmetic, f16 storage --
sits outside the inference feature and is covered by 11 tests that need
no weights on the machine.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Neither InsightFace export parses as shipped -- SCRFD fails at its input
node, ArcFace at the first Conv -- which is the same wall dr-segment hit
on YOLO's dynamic export. Both load cleanly with the input dims frozen,
so the pure-Rust runtime holds for the face pipeline too.
tools/fix-face-model-shapes.sh does the freezing, and exists so the
artefact is reproducible rather than a binary someone once produced. It
takes two forms because the two graphs need different ones: ArcFace's
batch is a named dim_param, SCRFD's H and W are dynamic but unnamed.
Also notes YuNet loading with no intervention, which matters for the
licence question in faces.md 2.3.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
FR-CULL-8..12 specify the subsystem in terms of "a 512-dimension embedding
from a stated model" and stop there, because D13 was open. This names the
models, and grounds them in the measurements and the working C++ pipeline in
../scene-actor-extraction rather than in a literature reading.
The licensing half of D13 stays open, but with a route through it: the
InsightFace weights are non-commercial and cannot be committed, so the app
ships the code and the user fetches the model. faces.model_id already makes
that a survivable choice.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolleandClaude Opus 5