> **Archived (July 2026).** This report covers the pre-opencv5 framework and the 4-model ArcFace/LVFace bake-off. It is superseded by the current [experiment log](model-bakeoff.md) for the opencv5 build. Kept for provenance; the numbers here are historical.

# Full experiment log

This page reports how the pipeline performs across three questions: which
embedding model is best, whether restricting the gallery to a film's
credited cast helps, and whether promoting confidently identified poses into
a per-film gallery annex helps. It also documents the replay architecture
that made testing all three questions in one pass practical, and every
caveat needed to trust the numbers.

Read [How we score against X-Ray](methodology-2026-07.md) first for what F1,
precision, recall, and misID mean in this report. All numbers below use the
per-second metric
([`scripts/optimizer/second_score.py`](https://REPOLINK/scripts/optimizer/second_score.py)).

r50 (ArcFace w600k-R50) is excluded from the detailed comparison below. Its
gallery was built with roughly 30% fewer reference images per actor than the
other three models on the identical source photos (10808 vs 15055 total
embeddings across the same 2418 actors), which confounds any direct
comparison of its scores against the others. It remains in the
[calibration curve comparison](best-model-2026-07.md#first-signal-calibration-curves),
which does not depend on the training benchmark.

## Why replay makes this affordable

Decoding video and running face detection, alignment, and embedding is the
expensive part of this pipeline. Everything downstream of that (tracking,
identity matching, scene aggregation) is cheap. KPN++'s node/network
structure means those two stages are separate components connected by
typed channels, so the expensive stage can run once per film, cache its
output, and the cheap stage can be re-run against that cache as many times
as needed with different Config values.

`scene_analyze --dump-embeddings out.h5` runs the expensive half once per
film and writes per-frame face detections and embeddings to HDF5
([`scripts/optimizer/SCHEMA.md`](https://REPOLINK/scripts/optimizer/SCHEMA.md)).
[`scripts/optimizer/replay.py`](https://REPOLINK/scripts/optimizer/replay.py)
then re-assembles the real C++ `face_tracker`, `identity_matcher`, and
`scene_tracker` nodes into a Python-driven KPN network and replays a
film's cached embeddings through them, varying `prob_threshold`,
`anneal_sec`, `extinction_sec`, and `expand_gallery` freely. No GPU
inference and no video decode happen during a replay; each one completes
in seconds. This is what makes a 512-evaluation differential-evolution
search per model, per gallery mode, per expansion setting, tractable, and
what made the full held-out validation across three models in this report
possible in one session rather than requiring three full re-encodes of the
benchmark set.

`optimize.py` runs `differential_evolution` over this replay function as its
objective, with DE-level parallelism (multiple candidate configs evaluated
concurrently, each spawning its own replay subprocesses) on top of it. The
practical ceiling on this machine's GPU was 8 concurrent replay processes;
9 silently degraded every score to 0.0% (well-formed output, wrong numbers,
not a crash), so `optimize.py` was run at `REPLAY_WORKERS=4 DE_WORKERS=2`.

## Search space

`popsize=10, maxiter=15` per combo (3 parameters, up to 512 evaluations,
usually stopping earlier on DE's convergence tolerance).
`anneal_sec`/`extinction_sec` bounds were widened from 1-30/1-15 to 1-60/1-60
partway through the sweep. r50's 4 combos finished before the widening and
used the old, narrower bounds; this is one more reason r50 is excluded from
direct comparison here.

## Training films and held-out films

9 films have dumped embeddings across all 4 models. 4 were used for
optimization:

- Café Society (62-cast)
- Lord of War (64-cast)
- Scarface (67-cast)
- Sound of Metal (14-cast)

5 were held out, never seen by any optimizer run:

- Benny & Joon
- Downton Abbey: A New Era
- Lovelace
- The Many Saints of Newark
- Valerian and the City of a Thousand Planets

## Gallery coverage per film

The gallery has reference embeddings for 2418 actors, but coverage of any
given film's credited cast varies widely. This was previously reported as
one flat number (67% of X-Ray cast lacking a reference embedding, averaged
across the whole benchmark); the per-film breakdown is:

| film | cast credited | in gallery | coverage |
|---|---|---|---|
| Lord of War | 64 | 13 | 20.3% |
| Scarface | 67 | 15 | 22.4% |
| The Many Saints of Newark | 48 | 13 | 27.1% |
| Café Society | 62 | 17 | 27.4% |
| Lovelace | 42 | 15 | 35.7% |
| Valerian and the City of a Thousand Planets | 36 | 13 | 36.1% |
| Benny & Joon | 23 | 12 | 52.2% |
| Downton Abbey: A New Era | 36 | 22 | 61.1% |
| Sound of Metal | 14 | 11 | 78.6% |

Two training films (Lord of War, Scarface) have the worst coverage in the
set, 20-22%. Their training-set F1 numbers below are partly capped by
missing references, not purely by model quality. Downton Abbey has 61%
coverage, the second-best in the benchmark, yet the worst held-out recall
of any film (39.4%, LVFace). Its recall problem is not primarily a coverage
problem; it is the extinction-bridging failure documented in the
[LVFace deep dive](lvface-deep-dive-2026-07.md#mechanism-1-extinction-bridging).
Reproduce with `scripts/docs/gallery_coverage_per_film.py`.

## Training results, 3 models × 2 gallery modes × 2 expansion settings

Ranked by F1. misid = FPI_misid, the count of true wrong-actor
identifications (naming someone not in the film's cast at all), distinct
from FPI, which also includes in-cast timing slips.

Each combo's row is its best **full-coverage** evaluation: the highest-F1 DE
evaluation in which all 4 training films replayed without a timeout (see
[Dropped-film scoring](#a-scoring-bug-worth-recording-dropped-film-evaluations)
below for why this qualifier is load-bearing and not the same as `argmax F1`
over the raw sweep).

| combo | F1 | P | R | TPI | FPI | misid | FN |
|---|---|---|---|---|---|---|---|
| LVFace-B_Glint360K_restricted_exp | 78.3% | 91.0% | 68.9% | 42830 | 3782 | 60 | 19492 |
| LVFace-B_Glint360K_restricted_noexp | 76.7% | 91.5% | 66.2% | 41149 | 3400 | 59 | 21173 |
| arcface_w600k_mbf_restricted_exp | 76.2% | 90.0% | 66.2% | 64328 | 7480 | 0 | 33234 |
| arcface_r18_restricted_exp | 75.5% | 87.6% | 66.5% | 41399 | 5666 | 60 | 20923 |
| LVFace-B_Glint360K_full_exp | 75.3% | 89.7% | 65.4% | 47757 | 3407 | 232 | 26966 |
| arcface_w600k_mbf_restricted_noexp | 75.0% | 91.1% | 63.9% | 39752 | 3465 | 60 | 22570 |
| arcface_r18_restricted_noexp | 73.5% | 91.3% | 61.7% | 38299 | 3220 | 60 | 24023 |
| LVFace-B_Glint360K_full_noexp | 72.3% | 88.3% | 61.8% | 40363 | 3503 | 244 | 25850 |
| arcface_w600k_mbf_full_exp | 72.0% | 87.7% | 61.4% | 39875 | 3729 | 240 | 26338 |
| arcface_w600k_mbf_full_noexp | 71.0% | 93.2% | 57.9% | 41699 | 2472 | 56 | 33024 |
| arcface_r18_full_exp | 69.1% | 87.6% | 57.7% | 37342 | 3119 | 242 | 28871 |
| arcface_r18_full_noexp | 66.6% | 91.3% | 53.1% | 34314 | 2362 | 107 | 31899 |

![All combos ranked by training-set F1](assets/images/rep4_matrix_f1.png)

The two clearest patterns: every model's best-scoring combo uses the
restricted gallery, and LVFace leads within both gallery modes. `full_exp`
(the shipped combination) is the best-scoring option that uses only
features the running application currently supports; restriction is not
wired into the application yet (see
[Whole vs. cast-restricted gallery](gallery-scope-2026-07.md)).

### A scoring bug worth recording: dropped-film evaluations

The numbers above are corrected ones. The raw `rep4_best_*.json` files, and an
earlier version of this table, reported a different `arcface_w600k_mbf_full_noexp`
row: **74.2% F1 at TPI 12645**, a third the TPI of every sibling combo. That was
not a better config; it was an artifact of how the optimizer aggregates.

`optimize.py` builds each candidate's score from only the films whose replay
subprocess returned (`per_film = [m for m in ex.map(_one, films) if m is not
None]`), then **averages** F1/precision/recall and **sums** TPI/FPI/misID over
just those survivors. When a film's replay times out (the sweep ran near the
8-process concurrency ceiling, so this happened intermittently), that film
silently drops from both. A candidate whose hardest film timed out is therefore
scored on an easier subset, and differential evolution, maximizing that score,
will happily converge onto exactly such a candidate. For `mbf_full_noexp` the
reported winner was one of 7 evaluations (out of 512) whose TPI had collapsed to
a partial-film subset; its median-coverage evaluations sit around 51686 TPI.

The fix here was to re-derive each combo's best row from its DE trajectory
(`experiments/trajectories/rep4_*.jsonl`), keeping only evaluations within 30% of
that combo's median TPI (full 4-film coverage) before taking the best F1. This
needs no re-running, the honest best configuration was already in the sweep,
just not the one `argmax F1` selected. Three combos moved: `mbf_full_noexp`
74.2% → **71.0%**, `LVFace_full_noexp` 72.4% → **72.3%** (and its misID, 0 → 244,
was itself a dropped-film artifact), `mbf_restricted_exp` 76.5% → **76.2%**. The
shipped LVFace `full_exp` winner was unaffected, its reported evaluation already
had full coverage (TPI 47757 ≈ median). `experiment_charts.py` applies the same
`clean_best` filter, so every figure on this page matches the corrected table.
The underlying `optimize.py` aggregation is also being fixed so a dropped-film
evaluation can never be selected as a winner again.

### Per-film training breakdown

The 75.3% LVFace training figure is a macro average across 4 films, not a
uniform result:

| film | LVFace F1 | mbf F1 | r18 F1 | best model |
|---|---|---|---|---|
| Café Society | 68.1% | 62.2% | 60.1% | LVFace |
| Lord of War | 75.6% | 77.2% | 75.6% | mbf |
| Scarface | 71.5% | 68.6% | 64.1% | LVFace |
| Sound of Metal | 78.8% | 76.5% | 71.6% | LVFace |

LVFace does not win every training film. mbf scores higher on Lord of War
(77.2% vs 75.6%). LVFace's own training-film range is 68.1% to 78.8%, a
10.7pp spread, smaller than the 37pp spread seen on held-out films but real.
Reproduce with `scripts/docs/run_holdout_all_models.py --films training`.

## Held-out validation, all 3 models

The training matrix above is training-set fit. Each model's own tuned
`full_exp` config was replayed against the 5 held-out films, scored the
same way:

| film | LVFace F1 | mbf F1 | r18 F1 |
|---|---|---|---|
| Benny & Joon | 83.0% | 78.5% | 77.1% |
| Lovelace | 77.5% | 73.7% | 72.2% |
| Valerian and the City of a Thousand Planets | 74.1% | 70.2% | 71.0% |
| Downton Abbey: A New Era | 56.2% | 55.0% | 53.0% |
| The Many Saints of Newark | 46.3% | 44.5% | 42.1% |
| **macro average** | **67.4%** | **64.4%** | **63.1%** |

LVFace scores highest on every one of the 5 held-out films; the ranking
never flips. Total misIDs across the 5 films: LVFace 1032, mbf 2197, r18
1224. LVFace has less than half mbf's misID count while also scoring
higher on every film. This directly confirms the model choice out of
sample; it is not inferred from the training numbers alone. See the
[LVFace deep dive](lvface-deep-dive-2026-07.md) for frame-level detail on where and
why LVFace still fails on the two worst films. Reproduce with
`scripts/docs/run_holdout_all_models.py`.

## Two effects in isolation: gallery scope and pose expansion

Averaging across the 3 compared models (r50 excluded) isolates each variable
from model choice.

**Gallery scope**, averaged over both expansion settings and all 3 models
(6 evaluations per row):

| scope | F1 | P | R | total misID |
|---|---|---|---|---|
| full | 71.1% | 89.6% | 59.6% | 1121 |
| restricted | 75.9% | 90.4% | 65.6% | 299 |

Restriction improves every metric at once. This is not a precision/recall
trade: +4.8pp F1, +6.0pp recall, and roughly a quarter the misIDs. Fewer
candidates in the matcher's search space means fewer opportunities for a
lookalike false match, and the recall gain shows this does not cost real
detections. Restriction is currently an offline optimizer technique, not a
runtime feature of the application; see
[Whole vs. cast-restricted gallery](gallery-scope-2026-07.md) for what building it
into the application would require.

**Pose expansion** (promoting a confidently identified track's novel-pose
views into a per-film gallery annex,
[`src/gallery/track_gallery.hpp`](https://REPOLINK/src/gallery/track_gallery.hpp)):

| scope | expansion | F1 | R | misID |
|---|---|---|---|---|
| full | off | 70.0% | 57.6% | 407 |
| full | on | 72.1% | 61.5% | 714 |
| restricted | off | 75.1% | 63.9% | 179 |
| restricted | on | 76.7% | 67.2% | 120 |

In restricted mode, expansion is a clean win: +1.6pp F1, +3.3pp recall,
misID drops. The annex only competes against the film's own roughly 15-actor
cast, so a new pose of a known actor is unlikely to be confused with someone
else. In full mode, expansion buys +2.1pp F1 and +3.9pp recall but at a real
cost: misID rises from 407 to 714 as the same new-pose view now competes
against the full 2418-actor gallery, where a confidently learned pose is more
likely to match the wrong person. On the full gallery it is a recall-vs-misID
trade, not a free gain. This training-set effect
did not reproduce on held-out data; see
[Does pose expansion help?](pose-expansion-2026-07.md) for the full held-out test
and the two methodology bugs caught while checking it.

## Calibration curves

Each gallery carries a fitted Platt sigmoid `P(match | sim) = σ(a·sim + b)`,
stored directly in the gallery HDF5
([`src/gallery/gallery_calibration.hpp`](https://REPOLINK/src/gallery/gallery_calibration.hpp)).
This measures discriminative power independent of whatever
`prob_threshold` a given run used:

![Calibrated P(match|similarity) for all four models](assets/images/calibration_curves.png)

LVFace has the steepest curve (`a=17.7` vs 15.3-16.2 for the ArcFace
variants) and the lowest P=0.5 decision boundary (similarity 0.23 vs
0.27-0.31), separating same-actor from different-actor pairs more
confidently at a lower similarity than any ArcFace variant tested,
including r50. Generated by
[`scripts/docs/calibration_chart.py`](https://REPOLINK/scripts/docs/calibration_chart.py).

## Extinction and anneal window search

Every one of the 512 DE evaluations for the winning LVFace `full_exp`
combo, plotted over the `prob_threshold` × `extinction_sec` plane:

![DE search landscape: 512 evaluations over prob_threshold × extinction_sec](assets/images/de_search_landscape.png)

Nearly everything scoring well sits at `extinction_sec` above 50, across a
wide range of thresholds. Short extinction windows are uniformly weaker:
under a strict threshold, there is no good configuration in that region of
the search space. The optimizer converged with `anneal_sec=59.2,
extinction_sec=59.2`, about 99% of the widened 60s bound, which raises an
open question not resolved in this round: does performance keep improving
past 60s, or does it plateau there. Not chased further this pass.

## Caveats

- r50's 4 combos used the older, narrower search bounds (1-30/1-15 instead
  of 1-60/1-60) and are further confounded by its thinner gallery. Excluded
  from all comparisons above except calibration.
- The shipped defaults use `full_exp` (75.3% training F1), not the
  higher-scoring `restricted_exp` (78.3%), because cast restriction is not
  a runtime feature of the application yet.
- `expand_gallery` is mode-dependent, not a free win. Averaged across models
  on the full gallery it trades misIDs for recall (see the pose-expansion
  table). For LVFace specifically, though, `full_exp` beats `full_noexp` on
  every axis at once (F1 75.3 vs 72.3, precision 89.7 vs 88.3, recall 65.4 vs
  61.8, misID 232 vs 244), so the shipped `full_exp` is a clean choice for
  this model, not an F1-vs-safety trade. (An earlier version of this page
  reported `full_noexp` at 72.4% with zero misIDs and higher precision, which
  made it look like the safer option; that was the dropped-film artifact
  described above, not a real property of the config.)
- Switching the default model is an operational change: any gallery built
  from a different model's embeddings must be rebuilt before the new
  default takes effect.

## Reproduce

```bash
# 4-film training matrix, all 4 models × 2 gallery modes × 2 expansion settings
bash experiments/run_rep4_subprocess.sh

# single combo
SAE_EXPAND=1 REPLAY_WORKERS=4 DE_WORKERS=2 python3 scripts/optimizer/optimize.py \
    --manifest experiments/manifests/rep4_LVFace-B_Glint360K_full.json \
    --gallery experiments/galleries/gallery_LVFace-B_Glint360K.h5 \
    --params prob_threshold:0.5:0.999 anneal_sec:1:60 extinction_sec:1:60 \
    --popsize 10 --maxiter 15 --trajectory traj.jsonl --out best.json

# held-out validation, all 3 models, 5 films
python3 scripts/docs/run_holdout_all_models.py --out docs_data/holdout_all_models.json

# per-film training breakdown, all 3 models, 4 films
python3 scripts/docs/run_holdout_all_models.py --films training --out docs_data/training_per_film.json

# gallery coverage per film
python3 scripts/docs/gallery_coverage_per_film.py --out docs_data/gallery_coverage_per_film.json

# regenerate this page's charts from experiments/ artifacts
python3 scripts/docs/experiment_charts.py --out-dir docs/assets/images

# one frame per distinct out-of-cast name across all 9 films (used in the deep dive)
python3 scripts/docs/first_fpi_frames.py
```

See also the session log
[`experiments/SESSION_STATE.md`](https://REPOLINK/experiments/SESSION_STATE.md).
