{
  "date": "2026-10-21",
  "scope": "Five synthetic fixtures executed in local browser harness using unchanged production source snapshot; browser encoded PNG links saved via DOM. Not live file-picker uploads.",
  "rows": [
    {
      "id": "clean-1024",
      "width": 1024,
      "height": 768,
      "kind": "clean",
      "input_sha256": "cc99c875d43197258b91143c5764474997a1034669b2cde36bfebbe3457df679",
      "gate": false,
      "file_bytes_identical": true,
      "max_alpha_difference": 0,
      "changed_alpha_pixels": 0,
      "max_rgb_difference_from_file": 0,
      "max_visible_rgb_difference_from_file": 0,
      "outside_box_rgb_changed_pixels_vs_file": 0,
      "outside_box_rgb_changed_pixels_vs_decoded_canvas": 733078,
      "transparent_rgb_changed_pixels": 0,
      "chosen_box": null,
      "output_sha256": "cc99c875d43197258b91143c5764474997a1034669b2cde36bfebbe3457df679",
      "outside_box_composite_max_on_0": 0,
      "outside_box_composite_max_on_255": 0
    },
    {
      "id": "marked-1024",
      "width": 1024,
      "height": 768,
      "kind": "marked",
      "input_sha256": "056c3be0e6dc054cb021f1d09bc1d267e18aa372c49e56f2ace7274bb83c3757",
      "gate": true,
      "file_bytes_identical": false,
      "max_alpha_difference": 0,
      "changed_alpha_pixels": 0,
      "max_rgb_difference_from_file": 226,
      "max_visible_rgb_difference_from_file": 112,
      "outside_box_rgb_changed_pixels_vs_file": 730774,
      "outside_box_rgb_changed_pixels_vs_decoded_canvas": 0,
      "transparent_rgb_changed_pixels": 98304,
      "chosen_box": {
        "x": 944,
        "y": 688,
        "width": 48,
        "height": 48
      },
      "output_sha256": "e3ea68de53d8536aad81fc7a0c93fc8a531feae3d0dad493965b63d7ea081f8e",
      "outside_box_composite_max_on_0": 0,
      "outside_box_composite_max_on_255": 0
    },
    {
      "id": "clean-1200",
      "width": 1200,
      "height": 896,
      "kind": "clean",
      "input_sha256": "2a6ad291cdf083e9189ad9f3749f0ea4f65686f08db039f888b1843fa31fdab1",
      "gate": false,
      "file_bytes_identical": true,
      "max_alpha_difference": 0,
      "changed_alpha_pixels": 0,
      "max_rgb_difference_from_file": 0,
      "max_visible_rgb_difference_from_file": 0,
      "outside_box_rgb_changed_pixels_vs_file": 0,
      "outside_box_rgb_changed_pixels_vs_decoded_canvas": 995641,
      "transparent_rgb_changed_pixels": 0,
      "chosen_box": null,
      "output_sha256": "2a6ad291cdf083e9189ad9f3749f0ea4f65686f08db039f888b1843fa31fdab1",
      "outside_box_composite_max_on_0": 0,
      "outside_box_composite_max_on_255": 0
    },
    {
      "id": "marked-1200",
      "width": 1200,
      "height": 896,
      "kind": "marked",
      "input_sha256": "bb03f446188e71def9085bc1c7a1ed204dcc7ccc23793c707cb2da9facd188f8",
      "gate": true,
      "file_bytes_identical": false,
      "max_alpha_difference": 0,
      "changed_alpha_pixels": 0,
      "max_rgb_difference_from_file": 190,
      "max_visible_rgb_difference_from_file": 98,
      "outside_box_rgb_changed_pixels_vs_file": 987647,
      "outside_box_rgb_changed_pixels_vs_decoded_canvas": 0,
      "transparent_rgb_changed_pixels": 134400,
      "chosen_box": {
        "x": 1040,
        "y": 736,
        "width": 96,
        "height": 96
      },
      "output_sha256": "3115818f46e92e7b7c0cb509b66d5faf765e42595d0e2180764ec79e44160cdb",
      "outside_box_composite_max_on_0": 0,
      "outside_box_composite_max_on_255": 0
    },
    {
      "id": "marked-opaque-1024",
      "width": 1024,
      "height": 768,
      "kind": "marked",
      "input_sha256": "585ba69089200a13b5225e2e4ea55bcc433bd4f7c5c676f16fe6d177ee895661",
      "gate": true,
      "file_bytes_identical": false,
      "max_alpha_difference": 0,
      "changed_alpha_pixels": 0,
      "max_rgb_difference_from_file": 110,
      "max_visible_rgb_difference_from_file": 110,
      "outside_box_rgb_changed_pixels_vs_file": 0,
      "outside_box_rgb_changed_pixels_vs_decoded_canvas": 0,
      "transparent_rgb_changed_pixels": 0,
      "chosen_box": {
        "x": 944,
        "y": 688,
        "width": 48,
        "height": 48
      },
      "output_sha256": "2cbc6628bab28c9b29ab89c210923276946b9a980a4e04625b7f4e5e7c0ad4cb",
      "outside_box_composite_max_on_0": 0,
      "outside_box_composite_max_on_255": 0
    }
  ],
  "definitions": {
    "alpha": "maximum absolute decoded input/output Alpha channel difference, integer 0..255; changed pixels count nonzero differences",
    "outside_box_rgb": "pixels with any RGB channel changed outside selected cleanup box; compare separately against raw PNG decode and browser decoded input canvas",
    "hidden_rgb": "pixels whose input Alpha equals zero; differences in RGB there do not imply visible color differences",
    "composite": "Round((RGB*Alpha + background*(255-Alpha))/255); compare output/input outside chosen box separately on black=0 and white=255."
  },
  "engine_hashes": {
    "app.js": "3a2f32556201e1fbd6e700d343dffef218677611f3c9e9d8c5f6f7c9c270e085",
    "alpha-maps.js": "69fc428ed9cdf7769ca63d2d70c2b5d661acbc88adf3ff1632f882a63c0f98ed",
    "watermark-gate.js": "40eeb519cc83fbcad8a12a7c7a43cf43e37b4c2fde9ccb7aa2a601db0bcee6ea"
  }
}