{
  "meta": {
    "generated": "2026-10-03T18:07:04.452Z",
    "canvas": "2000x2000",
    "sharp": {
      "aom": "3.13.1",
      "archive": "3.8.2",
      "cairo": "1.18.4",
      "cgif": "0.5.0",
      "exif": "0.6.25",
      "expat": "2.7.3",
      "ffi": "3.5.2",
      "fontconfig": "2.17.1",
      "freetype": "2.14.1",
      "fribidi": "1.0.16",
      "glib": "2.86.1",
      "harfbuzz": "12.1.0",
      "heif": "1.20.2",
      "highway": "1.3.0",
      "imagequant": "2.4.1",
      "lcms": "2.17",
      "mozjpeg": "0826579",
      "pango": "1.57.0",
      "pixman": "0.46.4",
      "png": "1.6.50",
      "proxy-libintl": "0.5",
      "rsvg": "2.61.2",
      "spng": "0.7.4",
      "tiff": "4.7.1",
      "vips": "8.17.3",
      "webp": "1.6.0",
      "xml2": "2.15.1",
      "zlib-ng": "2.2.5",
      "sharp": "0.34.5"
    },
    "script": "backend/scripts/white-background-study.ts"
  },
  "results": [
    {
      "id": "clean-png",
      "title": "Pure white, saved as PNG",
      "what": "Background drawn at exactly 255 and saved losslessly. The control.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 0,
        "offWhiteShare": 0,
        "darkestValue": 255
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "jpeg-q100",
      "title": "Pure white, saved as JPEG quality 100",
      "what": "The control image, re-encoded as JPEG at quality 100 (libjpeg via sharp, 4:2:0 chroma subsampling, sharp's default).",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 3905,
        "offWhiteShare": 0.12,
        "darkestValue": 236
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "jpeg-q95",
      "title": "Pure white, saved as JPEG quality 95",
      "what": "The control image, re-encoded as JPEG at quality 95 (libjpeg via sharp, 4:2:0 chroma subsampling, sharp's default).",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 7498,
        "offWhiteShare": 0.22,
        "darkestValue": 232
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "jpeg-q90",
      "title": "Pure white, saved as JPEG quality 90",
      "what": "The control image, re-encoded as JPEG at quality 90 (libjpeg via sharp, 4:2:0 chroma subsampling, sharp's default).",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 10117,
        "offWhiteShare": 0.3,
        "darkestValue": 222
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "jpeg-q80",
      "title": "Pure white, saved as JPEG quality 80",
      "what": "The control image, re-encoded as JPEG at quality 80 (libjpeg via sharp, 4:2:0 chroma subsampling, sharp's default).",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 14344,
        "offWhiteShare": 0.43,
        "darkestValue": 214
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "jpeg-q70",
      "title": "Pure white, saved as JPEG quality 70",
      "what": "The control image, re-encoded as JPEG at quality 70 (libjpeg via sharp, 4:2:0 chroma subsampling, sharp's default).",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 16731,
        "offWhiteShare": 0.5,
        "darkestValue": 210
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "backdrop-254",
      "title": "Backdrop at 254,254,254",
      "what": "A backdrop that looks white on screen but is 254 on every channel, as a slightly underexposed white sweep is.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 3362938,
        "offWhiteShare": 100,
        "darkestValue": 254
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "backdrop-252",
      "title": "Backdrop at 252,252,252",
      "what": "A backdrop that looks white on screen but is 252 on every channel, as a slightly underexposed white sweep is.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 3362938,
        "offWhiteShare": 100,
        "darkestValue": 252
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "backdrop-250",
      "title": "Backdrop at 250,250,250",
      "what": "A backdrop that looks white on screen but is 250 on every channel, as a slightly underexposed white sweep is.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 3362938,
        "offWhiteShare": 100,
        "darkestValue": 250
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "soft-shadow",
      "title": "Soft shadow under the product",
      "what": "Pure white background with a blurred contact shadow below the bottle, as a product shot on a table usually has.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 101438,
        "offWhiteShare": 3.02,
        "darkestValue": 176
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "vignette",
      "title": "Light-box falloff",
      "what": "Pure white at the centre, dimming to 240 in the corners, the way a light box or a single softbox falls off.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 1466112,
        "offWhiteShare": 43.6,
        "darkestValue": 240
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    },
    {
      "id": "p3-to-srgb",
      "title": "Pure white, through a Display P3 round trip",
      "what": "The control image tagged as Display P3 and converted back to sRGB, as happens when a phone photo moves between colour profiles.",
      "before": {
        "backgroundPixels": 3362938,
        "offWhitePixels": 0,
        "offWhiteShare": 0,
        "darkestValue": 255
      },
      "after": {
        "size": "1600x1600",
        "backgroundPixels": 1789936,
        "offWhitePixels": 0
      }
    }
  ]
}