{
  "schemaVersion": 1,
  "recordType": "measurements-of-existing-browser-export-files",
  "definitions": {
    "nearWhite": "All three encoded 8-bit RGB channels are at least 250.",
    "darkChannel": "At least one encoded RGB channel is at most 64. This is a threshold statistic, not measured line quality or semantic detail.",
    "nonGray": "The three RGB channel values are not identical. Exact equality is used, not a perceptual color tolerance.",
    "opacity": "All output alpha values equal 255 in the recorded files; white is an opaque background, not transparency.",
    "dimensions": "The actual dimensions are read with Pillow. Predicted dimensions are separately calculated from the reviewed short-edge-768, multiple-of-8 preprocessing rule.",
    "scope": "Two local-browser outputs from two source photographs. These numbers do not establish contour accuracy, vector quality, benchmark performance or processing speed."
  },
  "cases": [
    {
      "id": "coffee",
      "input": {
        "file": "../../images/coffee.png",
        "bytes": 466706,
        "sha256": "cc02f8ca188b167c775a7101b5d767d1e71792cf762c33d6fa15a4599b5a8de7",
        "width": 600,
        "height": 400,
        "mode": "RGB",
        "pixels": 240000,
        "fullyOpaquePixels": 240000,
        "nearWhitePixels": 57,
        "nearWhitePercent": 0.02375,
        "anyChannelAtOrBelow64Pixels": 175067,
        "anyChannelAtOrBelow64Percent": 72.944583,
        "nonGrayPixels": 239991,
        "nonGrayPercent": 99.99625
      },
      "output": {
        "file": "coffee-output.png",
        "bytes": 978602,
        "sha256": "2c03380e242200544765cd8ffc85ee2b5a61ed40ef0f365009d14dff6dea04ac",
        "width": 1152,
        "height": 768,
        "mode": "RGBA",
        "pixels": 884736,
        "fullyOpaquePixels": 884736,
        "nearWhitePixels": 733464,
        "nearWhitePercent": 82.902018,
        "anyChannelAtOrBelow64Pixels": 28059,
        "anyChannelAtOrBelow64Percent": 3.171455,
        "nonGrayPixels": 28059,
        "nonGrayPercent": 3.171455
      },
      "dimensionCheck": {
        "observedOutput": [
          1152,
          768
        ],
        "predictedFromReviewedPreprocessing": [
          1152,
          768
        ],
        "matchesReviewedRule": true,
        "widthScale": 1.92,
        "heightScale": 1.92,
        "note": "Source and output are not compared pixel by pixel; dimensions differ and this script does not resample either file."
      }
    },
    {
      "id": "chelsea",
      "input": {
        "file": "../../images/chelsea.png",
        "bytes": 240512,
        "sha256": "596aa1e7cb875eb79f437e310381d26b338a81c2da23439704a73c4651e8c4bb",
        "width": 451,
        "height": 300,
        "mode": "RGB",
        "pixels": 135300,
        "fullyOpaquePixels": 135300,
        "nearWhitePixels": 0,
        "nearWhitePercent": 0.0,
        "anyChannelAtOrBelow64Pixels": 38508,
        "anyChannelAtOrBelow64Percent": 28.461197,
        "nonGrayPixels": 135272,
        "nonGrayPercent": 99.979305
      },
      "output": {
        "file": "chelsea-output.png",
        "bytes": 1105137,
        "sha256": "baae9b5692b9e5c98ccd03d90d26d316bc91ebd5a5a9d91ff1da882453117804",
        "width": 1152,
        "height": 768,
        "mode": "RGBA",
        "pixels": 884736,
        "fullyOpaquePixels": 884736,
        "nearWhitePixels": 673117,
        "nearWhitePercent": 76.081113,
        "anyChannelAtOrBelow64Pixels": 60021,
        "anyChannelAtOrBelow64Percent": 6.784058,
        "nonGrayPixels": 60021,
        "nonGrayPercent": 6.784058
      },
      "dimensionCheck": {
        "observedOutput": [
          1152,
          768
        ],
        "predictedFromReviewedPreprocessing": [
          1152,
          768
        ],
        "matchesReviewedRule": true,
        "widthScale": 2.554324,
        "heightScale": 2.56,
        "note": "Source and output are not compared pixel by pixel; dimensions differ and this script does not resample either file."
      }
    }
  ]
}