Outdoor Check Stop HAZMAT Placard Detection Using Synthetic Images and YOLOv5-Small
Bibliographic record
Abstract
Deep learning training is frequently supplemented with synthetic data. We propose a scheme to synthesize images of HAZMAT placards in outdoor environments (e.g., check stops) to train models for detection and classification. Our process has 3 levels of realism, with noise and other distortions, and can simulate day and nighttime images. We used our data to train YOLOv5-Small models and evaluated models over a test dataset of 4321 real outdoor check stop images containing 6738 placards across 16 classes. Respectively, the best models for similar and single-class placard groupings had 0.867 and 0.927 best half-precision test set mAP@0.5. Models run at 65 FPS on Nvidia’s AGX Xavier edge GPU single-board computer, and at 12 FPS on Nvidia’s Nano.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".