{
  "date": "2026-09-08",
  "setting": "Balanced",
  "site": "https://www.plumedocs.com/compress-pdf",
  "provenance": "Maker-commissioned synthetic samples, prepared and checked with AI assistance. Not an independent benchmark.",
  "renderer": "Poppler pdftoppm",
  "renderDpi": 150,
  "renderColor": "RGB",
  "samples": [
    {
      "id": "01-scanned-lecture",
      "title": "Scanned lecture",
      "note": "A scanned page with a JPEG image. The image stream stayed unchanged; the file saved 556 bytes.",
      "before": {
        "file": "inputs/01-scanned-lecture.pdf",
        "bytes": 943022,
        "sha256": "a9ec90bea91f333bf5cf5ee6413114941e184c37c298329f684f34c5cfa281cf"
      },
      "after": {
        "file": "outputs/01-scanned-lecture-balanced.pdf",
        "bytes": 942466,
        "sha256": "e0897fdaecefa5d62a0a5d4a99c7dccd6d6f1775cc448ec6b029f087597d07c0"
      },
      "bytesSaved": 556,
      "reductionPercent": 0.058959388010035814,
      "pagesBefore": 1,
      "pagesAfter": 1,
      "extractedTextCharacters": 0,
      "extractedTextIdentical": true,
      "pageGeometryIdentical": true,
      "renderPixelsIdenticalAt150Dpi": true
    },
    {
      "id": "02-image-heavy-poster",
      "title": "Image-heavy poster",
      "note": "A poster with two large raster images. Both image streams stayed unchanged; the file saved 719 bytes.",
      "before": {
        "file": "inputs/02-image-heavy-poster.pdf",
        "bytes": 9129371,
        "sha256": "fb3ea6742ed8f702d57d7a7d109f3bdd4b03fb5c421893ce46c47b8baae091f2"
      },
      "after": {
        "file": "outputs/02-image-heavy-poster-balanced.pdf",
        "bytes": 9128652,
        "sha256": "d9b24ee7dc3db973647ae92dbc6e21d303faf4bff05d563ab69c2a722d0a89b9"
      },
      "bytesSaved": 719,
      "reductionPercent": 0.00787567949642971,
      "pagesBefore": 1,
      "pagesAfter": 1,
      "extractedTextCharacters": 1246,
      "extractedTextIdentical": true,
      "pageGeometryIdentical": true,
      "renderPixelsIdenticalAt150Dpi": true
    },
    {
      "id": "03-text-document",
      "title": "Text document",
      "note": "A text-only page with no embedded images. The file saved 649 bytes while its extracted text stayed identical.",
      "before": {
        "file": "inputs/03-text-document.pdf",
        "bytes": 2648,
        "sha256": "1f09ee9bfae5fa541a1a661f994afe8ad2025c642d7c0de298f2178d6c9c1e0b"
      },
      "after": {
        "file": "outputs/03-text-document-balanced.pdf",
        "bytes": 1999,
        "sha256": "e6c15699ab10f31ae6c671d69eab7616bd315fc8f7e80389bce8efc5944b2997"
      },
      "bytesSaved": 649,
      "reductionPercent": 24.50906344410876,
      "pagesBefore": 1,
      "pagesAfter": 1,
      "extractedTextCharacters": 1063,
      "extractedTextIdentical": true,
      "pageGeometryIdentical": true,
      "renderPixelsIdenticalAt150Dpi": true
    }
  ],
  "compatibility": {
    "preparation": "The reversible ASCII85 wrapper was removed from the original poster image streams before the product run. Image pixel content, extracted text and page geometry were retained.",
    "before": {
      "file": "compatibility/02-poster-single-filter.pdf",
      "bytes": 7304086,
      "sha256": "61bca4bd8e0d0c9adbada68500d64664980095d71ff9967ca6f6f035dcf446d3"
    },
    "after": {
      "file": "compatibility/02-poster-single-filter-balanced.pdf",
      "bytes": 53592,
      "sha256": "243b95c3c0149edada9ce37b435f0efcea7f753de0dc551ec06a5898b4268949"
    },
    "bytesSaved": 7250494,
    "reductionPercent": 99.26627369940606,
    "preparationReductionPercent": 19.993546105202647,
    "preparationSavingsAttributedToProduct": false,
    "preparedInputRenderMatchesOriginalAt150Dpi": true,
    "outputRenderPixelsIdenticalAt150Dpi": false,
    "changedRenderPixels": 1172255,
    "changedRenderPixelsPercent": 26.91182783849988,
    "meanAbsoluteRgbDifference0To255": 0.32454297724241316,
    "maximumChannelDifference0To255": 9,
    "extractedTextCharacters": 1246,
    "extractedTextIdentical": true,
    "pageGeometryIdentical": true,
    "imageDimensionsBefore": [
      1800,
      1800
    ],
    "imageDimensionsAfter": [
      1600,
      1600
    ],
    "outputImageEncoding": "JPEG",
    "visualReview": "Subtle smoothing and color changes are visible at detail scale. Layout and caption text remain readable. This result is not lossless.",
    "detailCropPx": [
      83,
      1160,
      823,
      1460
    ]
  },
  "report": {
    "file": "PlumeDocs_Test_Report.pdf",
    "bytes": 3642824,
    "sha256": "2026f5124dca79fbb9bdd8cb5d9e1d9b2686cced8b911735d1939a20e02aeb8e"
  },
  "limitations": [
    "Three synthetic originals and one separately prepared variant are not a representative benchmark or a prediction for other files.",
    "Pixel comparisons apply only to this Poppler render at 150 dpi in RGB, not every viewer or print workflow.",
    "The scanned sample has no extractable text layer. This test does not establish OCR or screen-reader accessibility.",
    "This test does not establish upload behavior, security, standards compliance or a general compression guarantee.",
    "A nonfatal Fontconfig configuration warning appeared on text-bearing renders. All renders completed, used the same settings before and after, and were visually reviewed."
  ]
}