{
  "templateVersion": "DSE-OMR-v3.1-four-large-markers-only",
  "pageDimensions": [
    3093,
    4374
  ],
  "strictMarkerMode": true,
  "answerRegionBounds": {
    "left": 829,
    "top": 1598,
    "right": 2917,
    "bottom": 4170
  },
  "largeCornerMarkers": {
    "top_left": [
      720,
      1410
    ],
    "top_right": [
      3015,
      1410
    ],
    "bottom_left": [
      720,
      4285
    ],
    "bottom_right": [
      3015,
      4285
    ]
  },
  "largeMarkerOuterSize": 144,
  "largeMarkerNestedLevels": 5,
  "detection": {
    "minNestedDepth": 3,
    "minQuadrilateralAreaRatio": 0.2,
    "minHorizontalSpanRatio": 0.48,
    "minVerticalSpanRatio": 0.48,
    "maxMarkerSizeCv": 0.42,
    "candidateSideScaleRange": [
      0.38,
      2.5
    ],
    "maxCandidatesPerCorner": 8,
    "topBottomWidthRatioRange": [
      0.48,
      1.85
    ],
    "leftRightHeightRatioRange": [
      0.48,
      1.85
    ],
    "diagonalRatioRange": [
      0.55,
      1.8
    ]
  },
  "notes": [
    "This variant keeps only the four 144 px five-layer large corner markers.",
    "All 16 small markers between five-question groups have been removed.",
    "V3.1 strict full-page detection remains the first stage.",
    "Local corner-ROI rescue remains available when phone or hand shadow degrades one or two large markers.",
    "Recovered points must still pass full four-point geometry validation.",
    "No local group-marker correction is performed or required in this project."
  ],
  "localRescue": {
    "enabled": true,
    "minimumGlobalCandidates": 2,
    "maxRescueCorners": 2,
    "roiHalfWidthRatio": 0.22,
    "roiHalfHeightRatio": 0.2,
    "templateMatchThreshold": 0.4,
    "templateMatchScales": [
      0.68,
      0.78,
      0.88,
      0.98,
      1.08,
      1.18,
      1.28
    ],
    "templateMatchAngles": [
      -10,
      0,
      10
    ],
    "adaptiveBlockSize": 31,
    "adaptiveC": 7
  }
}