{
  "date": "2026-10-28",
  "method": "Geometric calculation on one AI-generated decorative image displayed in centered object-fit: cover frames. No user eye-tracking or external video service test.",
  "source": {
    "url": "https://www.yadongtoki3.top/assets/images/about.webp",
    "width": 400,
    "height": 286,
    "bytes": 17188,
    "origin": "AI-generated fictional adult portrait at a cafe, prepared as a 400x286 decorative image.",
    "sha256": "c7b7ae71a8649831384a2b17ad34ad619b61704a2e231f49520760f92399d794"
  },
  "records": [
    {
      "frame": "original",
      "source_visible_width": 400,
      "source_visible_height": 286,
      "excluded_area_percent": 0,
      "horizontal_clip_each_side": 0,
      "vertical_clip_each_side": 0,
      "editorial_observation": "The whole source frame remains visible."
    },
    {
      "frame": "16:9",
      "source_visible_width": 400,
      "source_visible_height": 225,
      "excluded_area_percent": 21.328671328671334,
      "horizontal_clip_each_side": 0,
      "vertical_clip_each_side": 30.5,
      "editorial_observation": "Top and bottom are clipped; horizontal context remains."
    },
    {
      "frame": "1:1",
      "source_visible_width": 286,
      "source_visible_height": 286,
      "excluded_area_percent": 28.500000000000004,
      "horizontal_clip_each_side": 57,
      "vertical_clip_each_side": 0,
      "editorial_observation": "The left and right background is reduced."
    },
    {
      "frame": "9:16",
      "source_visible_width": 160.875,
      "source_visible_height": 286,
      "excluded_area_percent": 59.78125000000001,
      "horizontal_clip_each_side": 119.5625,
      "vertical_clip_each_side": 0,
      "editorial_observation": "A narrow central section remains; most lateral context is excluded."
    }
  ],
  "limitations": [
    "Single image sample",
    "Fractional source coordinates are mathematical; device pixel rounding may differ",
    "Excluded area is not a measure of information importance or network byte savings",
    "Visual emphasis is editorial interpretation, not measured attention"
  ]
}