{
  "date": "2026-10-29",
  "subject": "A single synthetic chart; not a photograph or a video service sample",
  "method": {
    "sourcePixels": [
      1280,
      720
    ],
    "source": "/assets/chart-original.webp",
    "sourceEncoding": "lossless WebP",
    "encoder": "Pillow 12.3.0",
    "webpEncoder": "1.6.0",
    "resize": "LANCZOS",
    "qualityScope": "Pillow WebP encoder setting; not a percentage quality score",
    "count": 3,
    "displayTargetCssPixels": 640,
    "sourceBytes": 11360
  },
  "variants": [
    {
      "file": "/assets/chart-1280.webp",
      "width": 1280,
      "height": 720,
      "qualitySetting": 82,
      "bytes": 17528,
      "sha256": "f00612177aad5ed128299c31a3b282d75319214ee636f2576044d3f001108377"
    },
    {
      "file": "/assets/chart-320.webp",
      "width": 320,
      "height": 180,
      "qualitySetting": 82,
      "bytes": 3726,
      "sha256": "381f11497617a4eb6f8b63a0bd06462a09f08b90083d78907e7e8657dfc1e2a3"
    },
    {
      "file": "/assets/chart-q20.webp",
      "width": 1280,
      "height": 720,
      "qualitySetting": 20,
      "bytes": 10618,
      "sha256": "bc446f2888a795897d7d2eb2c368d2d58a815a2822a4be76ed23ae267938ad98"
    }
  ],
  "browserObservation": {
    "date": "2026-10-29",
    "platform": "Windows desktop Chrome",
    "viewportCssPixels": [
      1920,
      897
    ],
    "devicePixelRatio": 1,
    "imageDisplayCssPixels": [
      640,
      360
    ],
    "observationType": "Visual inspection of the three images on the same local article page, not a scored perceptual study.",
    "findings": [
      "The 2 px stripes merge into a gray block in sample B; the 8 px and 16 px stripes remain separated.",
      "The 2 px stripes remain visible in A and C. At this display size, differences between A and C are less obvious than the reduction in sample B.",
      "Small lettering looks blurred in B relative to A and C."
    ]
  },
  "limits": [
    "One synthetic chart, no population or real-service claims.",
    "File bytes are not measured loading time.",
    "A thumbnail cannot prove the resolution of the video it links to."
  ]
}