engine.py is the process-wide, thread-safe core the server is built on: one
YOLO instance behind a lock, thread-local matcher access, a classification pool
so detection is never starved, the stock catalog under its own lock, empty-slot
geometry normalized to a reference width (the detector's gap thresholds are
absolute pixels), and a small LRU of recent still images for later
classify/inspect calls. Detection output is normalized so every client sees the
same box shape.
tracking.py wraps ultralytics BYTETracker. The important part: ultralytics
mints track ids from a process-global counter and resets it when a tracker is
constructed, so with two live clients one client's ids would be re-issued while
the other still held cached labels. SessionTracker gives each tracker its own
counter and never touches the global one.
Measured defaults (bench_engine.py, M5): detection p50 26-29 ms on CPU vs
112 ms on MPS with byte-identical boxes, so device defaults to cpu; hybrid
classifies at ~51 ms/crop, 92 crops/s across 8 threads.
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Keeps the model's uncertainty out of the UI: decide_identity() separates raw
matcher scores into accepted / ambiguous / unknown / rejected, and only an
accepted result can name a SKU. Zero evidence is rejected, never a product.
observe.py adds frame-local observations and one-zone scan sessions (draft,
finalize, cancel, rescan) with replay, staleness and backpressure rules.
pipeline.process_click() now reports the identity level instead of failing
when the match is not accepted.
Incorporates earlier uncommitted session work in this repository
(identity.py, observe.py, yolo_adapter.py, test_observe.py, and the pipeline
hunk those needed); yolo_adapter keeps its decoded frame per thread so
concurrent sessions cannot swap images.
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
The recognition server will classify crops from several clients at once. Two
things blocked that:
- OpenCV Feature2D objects were shared across calls, so parallel
classify_crop() calls could corrupt each other. Each thread now gets its own
extractor set; the template cache is untouched.
- score_crop() is extracted from classify_crop() so callers that need every SKU
score (live track aggregation) do not have to re-derive it from the top-5
list. classify_crop() output is byte-identical to before (verified against the
pre-change module on 82 real crops x 4 methods).
- ShelfProductDetector accepts device/imgsz so the server can pin inference.
Dependencies: pin ultralytics to the version that wrote the checkpoint and that
the session tracker targets (8.4.153), add lap so ultralytics never
pip-installs it mid-request, and add websockets for the streaming endpoint.
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
