{
  "status": "Four measured cases; three Auto48 and one owner-approved Manual96; no Auto96 validation",
  "cases": [
    {
      "id": "conservatory",
      "original": "gemini-original-2026-10-18-conservatory.jpg",
      "composited": "composited-input-2026-10-18-conservatory.png",
      "cleaned": "cleaned-2026-10-18-conservatory.png",
      "date": "2026-10-18",
      "origin": "Owner provided these JPEG files and identified them as Gemini-generated; no native visible watermark was seen on inspection.",
      "width": 896,
      "height": 1200,
      "format": "JPEG",
      "tier": 48,
      "margin": 32,
      "box_x": 816,
      "box_y": 1120,
      "box_width": 48,
      "box_height": 48,
      "strength": "1.00",
      "original_bytes": 1387842,
      "input_bytes": 2426698,
      "original_sha256": "fa77d18d77668458aa52b62f2eb59b43abaa0dd3a1250d6bdea9ece12be1196d",
      "composited_sha256": "7580735d9d7f263dcd30dab4fc040144f7bde1538e3c8bc895c1d4d56f3e9f6c",
      "input_vs_ground_truth": {
        "max_channel_error": 129,
        "absolute_error_sum_rgb": 226455,
        "channel_count_rgb": 3225600,
        "mean_absolute_error_rgb": "0.07",
        "mean_absolute_error_rgb_unrounded": 0.0702055431547619,
        "mean_absolute_error_box_rgb": "32.76",
        "changed_pixels_inside_box": 883,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 883
      },
      "live_tool_readout": "image 896×1200 · watermark 48×48 px at x=816, y=1120",
      "browser_processing": {
        "url": "https://watermarkundo.com/",
        "browser": "ChatGPT in-app browser; Chrome native control unavailable",
        "mode": "Auto",
        "strength": "1.00",
        "horizontal_offset": 0,
        "vertical_offset": 0,
        "show_box": false,
        "downloaded_as": "composited-input-2026-10-18-conservatory-no-watermark.png"
      },
      "cleaned_vs_ground_truth": {
        "max_channel_error": 1,
        "absolute_error_sum_rgb": 1099,
        "channel_count_rgb": 3225600,
        "mean_absolute_error_rgb": "0.00",
        "mean_absolute_error_rgb_unrounded": 0.0003407118055555556,
        "mean_absolute_error_box_rgb": "0.16",
        "changed_pixels_inside_box": 678,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 678
      },
      "cleaned_bytes": 2983989,
      "cleaned_sha256": "e5c433632c7e0d159c3b968e4592eab3bcc6904714b5f2681b488fc8e3c35b4c",
      "auto_tier": 48,
      "selection_mode": "Auto"
    },
    {
      "id": "living-room",
      "original": "gemini-original-2026-10-18-living-room.jpg",
      "composited": "composited-input-2026-10-18-living-room.png",
      "cleaned": "cleaned-2026-10-18-living-room.png",
      "date": "2026-10-18",
      "origin": "Owner provided these JPEG files and identified them as Gemini-generated; no native visible watermark was seen on inspection.",
      "width": 1376,
      "height": 768,
      "format": "JPEG",
      "tier": 48,
      "margin": 32,
      "box_x": 1296,
      "box_y": 688,
      "box_width": 48,
      "box_height": 48,
      "strength": "1.00",
      "original_bytes": 1032525,
      "input_bytes": 1968169,
      "original_sha256": "f3f98ba2eda28399ad2ceb73bfa6c3ecaaf5ee496ff341a53c139ad5cb06126a",
      "composited_sha256": "a9b360850f1d88439eb03191536a81b63e6a78d7452ac8b2887b780ce81180de",
      "input_vs_ground_truth": {
        "max_channel_error": 128,
        "absolute_error_sum_rgb": 220862,
        "channel_count_rgb": 3170304,
        "mean_absolute_error_rgb": "0.07",
        "mean_absolute_error_rgb_unrounded": 0.06966587431363049,
        "mean_absolute_error_box_rgb": "31.95",
        "changed_pixels_inside_box": 883,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 883
      },
      "live_tool_readout": "image 1376×768 · watermark 48×48 px at x=1296, y=688",
      "browser_processing": {
        "url": "https://watermarkundo.com/",
        "browser": "ChatGPT in-app browser; Chrome native control unavailable",
        "mode": "Auto",
        "strength": "1.00",
        "horizontal_offset": 0,
        "vertical_offset": 0,
        "show_box": false,
        "downloaded_as": "composited-input-2026-10-18-living-room-no-watermark.png"
      },
      "cleaned_vs_ground_truth": {
        "max_channel_error": 1,
        "absolute_error_sum_rgb": 1213,
        "channel_count_rgb": 3170304,
        "mean_absolute_error_rgb": "0.00",
        "mean_absolute_error_rgb_unrounded": 0.00038261315003229975,
        "mean_absolute_error_box_rgb": "0.18",
        "changed_pixels_inside_box": 710,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 710
      },
      "cleaned_bytes": 2559346,
      "cleaned_sha256": "9f901abfa77630dd9aed12609c347f76ee04a7a0447b53f26aa4a46b0bcc130e",
      "auto_tier": 48,
      "selection_mode": "Auto"
    },
    {
      "id": "vase",
      "original": "gemini-original-2026-10-18-vase.jpg",
      "composited": "composited-input-2026-10-18-vase.png",
      "cleaned": "cleaned-2026-10-18-vase.png",
      "date": "2026-10-18",
      "origin": "Owner provided these JPEG files and identified them as Gemini-generated; no native visible watermark was seen on inspection.",
      "width": 1024,
      "height": 1024,
      "format": "JPEG",
      "tier": 48,
      "margin": 32,
      "box_x": 944,
      "box_y": 944,
      "box_width": 48,
      "box_height": 48,
      "strength": "1.00",
      "original_bytes": 555470,
      "input_bytes": 1113765,
      "original_sha256": "36fc76b3c86e0900c378779aa1bce907127011f2cb58b30e193716e88463bbd5",
      "composited_sha256": "33733d3b4b1f1380a7a5c5e976338d48966c274324c53188ae2b84a35dd03947",
      "input_vs_ground_truth": {
        "max_channel_error": 47,
        "absolute_error_sum_rgb": 90478,
        "channel_count_rgb": 3145728,
        "mean_absolute_error_rgb": "0.03",
        "mean_absolute_error_rgb_unrounded": 0.028762181599934895,
        "mean_absolute_error_box_rgb": "13.09",
        "changed_pixels_inside_box": 883,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 883
      },
      "live_tool_readout": "image 1024×1024 · watermark 48×48 px at x=944, y=944",
      "browser_processing": {
        "url": "https://watermarkundo.com/",
        "browser": "ChatGPT in-app browser; Chrome native control unavailable",
        "mode": "Auto",
        "strength": "1.00",
        "horizontal_offset": 0,
        "vertical_offset": 0,
        "show_box": false,
        "downloaded_as": "composited-input-2026-10-18-vase-no-watermark.png"
      },
      "cleaned_vs_ground_truth": {
        "max_channel_error": 1,
        "absolute_error_sum_rgb": 1165,
        "channel_count_rgb": 3145728,
        "mean_absolute_error_rgb": "0.00",
        "mean_absolute_error_rgb_unrounded": 0.00037034352620442707,
        "mean_absolute_error_box_rgb": "0.17",
        "changed_pixels_inside_box": 620,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 620
      },
      "cleaned_bytes": 1633885,
      "cleaned_sha256": "cd8b370758bc3fcf02c75e97996edff7b5a21ec61c776c45bffb0858f109a938",
      "auto_tier": 48,
      "selection_mode": "Auto"
    },
    {
      "id": "landscape-96",
      "original": "gemini-original-2026-10-18-coast.jpg",
      "composited": "composited-input-2026-10-18-coast.png",
      "cleaned": "cleaned-2026-10-18-coast.png",
      "date": "2026-10-18",
      "origin": "Owner-provided Gemini image, copied byte for byte from image_280d10c4.zip; no native visible sparkle seen.",
      "manual_tier": 96,
      "manual_tier_authorization": "Owner explicitly agreed in this chat to manual96 controlled test on existing1200x896 image; not Auto96 validation.",
      "width": 1200,
      "height": 896,
      "format": "JPEG",
      "tier": 96,
      "auto_tier": 48,
      "selection_mode": "Manual",
      "margin": 64,
      "box_x": 1040,
      "box_y": 736,
      "box_width": 96,
      "box_height": 96,
      "strength": "1.00",
      "original_bytes": 1231222,
      "input_bytes": 2147050,
      "original_sha256": "fe67f5272aa9bb8e452e693d9f03707e6e189d16d024ec94905c4aef30e3a704",
      "composited_sha256": "a357fa0b063fb0c580d7674ccbe458cb4b4e34f8815e04f2c34cae7acf47611d",
      "input_vs_ground_truth": {
        "max_channel_error": 131,
        "absolute_error_sum_rgb": 1127206,
        "channel_count_rgb": 3225600,
        "mean_absolute_error_rgb": "0.35",
        "mean_absolute_error_rgb_unrounded": 0.3494562251984127,
        "mean_absolute_error_box_rgb": "40.77",
        "changed_pixels_inside_box": 4634,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 4634
      },
      "live_tool_readout": "image 1200×896 · watermark 96×96 px at x=1040, y=736",
      "live_auto_readout": "image 1200×896 · watermark 48×48 px at x=1120, y=816",
      "browser_processing": {
        "url": "https://watermarkundo.com/",
        "browser": "ChatGPT in-app browser; Chrome native control unavailable",
        "mode": "Manual96",
        "strength": "1.00",
        "horizontal_offset": 0,
        "vertical_offset": 0,
        "show_box": false,
        "downloaded_as": "composited-input-2026-10-18-coast-no-watermark.png"
      },
      "cleaned_vs_ground_truth": {
        "max_channel_error": 1,
        "absolute_error_sum_rgb": 4336,
        "channel_count_rgb": 3225600,
        "mean_absolute_error_rgb": "0.00",
        "mean_absolute_error_rgb_unrounded": 0.0013442460317460317,
        "mean_absolute_error_box_rgb": "0.16",
        "changed_pixels_inside_box": 2679,
        "changed_pixels_outside_box": 0,
        "changed_pixels_total": 2679
      },
      "cleaned_bytes": 2727435,
      "cleaned_sha256": "02993cda7104e4483a98616eb4ddf5d0ff0ebe83c8ec1cc82456b2fef29b8523"
    }
  ],
  "method": {
    "baseline": "RGB pixels decoded by Pillow from owner-supplied JPEG originals, preserved byte for byte",
    "composition": "quantize to uint8 by floor(value+0.5); value=(1-alpha)*ground_truth+alpha*logo",
    "alpha": "Exact signed Float32 map from the unchanged site alpha-maps.js; magnitude clipped at 0.99; logo=0 if signed map <0 else 255; ignore support where max(0,abs(raw)-3/255)<0.002; gain=1.00",
    "alpha_map_sha256": "69fc428ed9cdf7769ca63d2d70c2b5d661acbc88adf3ff1632f882a63c0f98ed",
    "geometry": "Auto: width>1024 AND height>1024: size96 margin64; otherwise size48 margin32. Owner-approved fourth case manually uses size96 margin64 on1200x896; it does not validate Auto96. x=width-margin-size; y=height-margin-size; left/top inclusive, right/bottom exclusive",
    "measurement": "RGB, scale0..255; max over all channels; MAE=sum absolute RGB differences/(width*height*3); count pixel once if any RGB channel differs; compare cleaned with ground truth, not input",
    "versions": {
      "Pillow": "12.3.0",
      "NumPy": "2.3.5"
    },
    "cleanup": "Not implemented in this script. Cleaned files must be downloaded from live tool: first three Auto48, fourth manually selected96; strength1.00, offsets0, overlay off.",
    "limitations": "Known-map composited inputs, not native Gemini watermarked downloads; not success rate or evidence for all images; SynthID, metadata and mobile processing not tested."
  }
}