{
  "image_path": "assets/test_sample.jpg",
  "timestamp": "2025-01-15T14:32:07Z",
  "sensor_id": "station_oge_01",
  "pixel_size_um": 2.5,
  "image_dimensions": {
    "width": 416,
    "height": 416
  },
  "total_count": 4,
  "particles": [
    {
      "particle_id": 1,
      "bbox": [
        44,
        260,
        179,
        343
      ],
      "bbox_normalized": [
        0.268,
        0.7248,
        0.3245,
        0.1995
      ],
      "size_mm": 0.3962,
      "area_px2": 11205,
      "shape": "fiber",
      "shape_confidence": 0.9898,
      "detection_confidence": 0.9215,
      "gt_shape": "fiber",
      "correct": true
    },
    {
      "particle_id": 2,
      "bbox": [
        116,
        118,
        163,
        181
      ],
      "bbox_normalized": [
        0.3353,
        0.3594,
        0.113,
        0.1514
      ],
      "size_mm": 0.1965,
      "area_px2": 2961,
      "shape": "foam",
      "shape_confidence": 0.9256,
      "detection_confidence": 0.8792,
      "gt_shape": "foam",
      "correct": true
    },
    {
      "particle_id": 3,
      "bbox": [
        58,
        207,
        118,
        272
      ],
      "bbox_normalized": [
        0.2115,
        0.5757,
        0.1442,
        0.1562
      ],
      "size_mm": 0.2211,
      "area_px2": 3900,
      "shape": "fragment",
      "shape_confidence": 0.9384,
      "detection_confidence": 0.8239,
      "gt_shape": "fragment",
      "correct": true
    },
    {
      "particle_id": 4,
      "bbox": [
        277,
        168,
        332,
        236
      ],
      "bbox_normalized": [
        0.732,
        0.4856,
        0.1322,
        0.1635
      ],
      "size_mm": 0.2186,
      "area_px2": 3740,
      "shape": "fragment",
      "shape_confidence": 0.9769,
      "detection_confidence": 0.8402,
      "gt_shape": "fragment",
      "correct": true
    }
  ],
  "shape_distribution": {
    "fragment": 2,
    "fiber": 1,
    "film": 0,
    "bead": 0,
    "foam": 1
  },
  "mean_size_mm": 0.2581,
  "size_range_mm": [
    0.1965,
    0.3962
  ],
  "processing_time_ms": 181.01,
  "classifier_accuracy_on_demo": 1.0,
  "model_versions": {
    "detector": "TinyYOLO-v1 (5 epochs on 200-sample synthetic subset)",
    "classifier": "EfficientNet-B0-MPClassifier-v1 (10 epochs, 1500 samples, val_acc=0.95)"
  },
  "data_quality": "synthetic",
  "pipeline_note": "Demo uses ground-truth bounding boxes + trained classifier. Production: TinyYOLO \u2192 NMS \u2192 MPClassifier. Field accuracy: 60-70% (camera only); ~85% with UV fluorescence (MP-Set dataset).",
  "downstream": {
    "m3_input": "particle counts, shape distributions, coordinates \u2192 M3 Graph GNN source attribution",
    "m4_display": "shape_distribution + total_count \u2192 M4 Dashboard real-time display"
  }
}