# scene-actor-extraction

A face-recognition pipeline that finds when each actor appears on screen in a
film or TV episode — built on [KPN++](https://gitea.tourolle.paris/dtourolle/KPN)
(a C++20 Kahn Process Network library) for the detect → track → match → scene
pipeline, with a Jellyfin-integrated gallery and an X-Ray-validated optimizer.

This is what a good second looks like — one sampled frame from a held-out film,
19 faces named, all 19 correct, the rest honestly declared unknown:

![19 correct identifications in one wedding shot, Downton Abbey: A New Era](assets/images/downton_wedding_19_correct.jpg)

And this is why the work isn't done: on this same film the same config misses
6 in 10 of the actor-seconds X-Ray says are present, and on the worst held-out
film it reports ghost actors over empty walls — at 100% confidence. Both
stories, with the evidence, are in the pages below.

## Start here — four questions this bake-off answers

- **[Which model is best?](best-model.md)** — calibration curves first
  (discriminative power, independent of any threshold), then F1 on the actual
  benchmark. LVFace-B Glint360K wins both.
- **[Whole gallery vs. limited (cast-restricted) gallery](gallery-scope.md)** —
  restricting the matcher to a film's credited cast is a clean win on every
  axis (+3.3pp F1, less than a third the misIDs), but isn't a shipped runtime
  feature yet.
- **[Does pose expansion help?](pose-expansion.md)** — a real training-set
  effect that didn't reproduce on 5 held-out films once two methodology bugs
  were caught and fixed. An honest null result, not a forced narrative.
- **[Deep dive: LVFace-B Glint360K](lvface-deep-dive.md)** — the winning
  model's held-out generalization gap, its two real failure modes (frozen-bbox
  "ghost tracks"), and one case where it correctly identified an actor that
  the X-Ray ground truth itself failed to credit.

## The full technical log

- **[Model bake-off + threshold re-tune](model-bakeoff.md)** —
  the complete experiment log behind the four pages above: the ROCm teardown
  deadlock root cause and fix, DE concurrency tuning, the full 16-combo
  results table, and every caveat. This is where the shipped
  [`src/config.hpp`](https://REPOLINK/src/config.hpp) defaults come from.
- **[Optimizer experiments (prior round)](optimizer-experiments.md)** — the
  earlier scene-union-metric tuning pass, superseded by the per-second metric
  used in the bake-off but kept for the ground-truth/architecture background.
- **[Service conversion (proposal)](service-conversion.md)** — design sketch
  for an idle-GPU Docker worker, not yet built.

## Reproducing the benchmarks

Gallery `.h5` files, embedding dumps, the X-Ray corpus, montage frame images,
and DE trajectories are not committed to this repository — they're pushed to
the Gitea package registry and pulled on demand:

```bash
scripts/artifacts/pull_artifacts.sh galleries
scripts/artifacts/pull_artifacts.sh experiment-data
scripts/artifacts/pull_artifacts.sh montage-frames <film-slug>
```

See [`scripts/artifacts/push_artifacts.sh`](https://REPOLINK/scripts/artifacts/push_artifacts.sh)
for the upload side (requires a `GITEA_TOKEN` with package write scope).