{
  "created_at_local": "2026-10-29 Asia/Shanghai",
  "method": "Create one synthetic 1200x840 geometric JPEG with dummy GPS (0 N, 0 E), camera-label and date tags; inspect EXIF; decode/re-encode at the same JPEG quality without carrying EXIF; inspect again.",
  "safety": "No portrait, real camera, or real location was used; dummy GPS is 0,0.",
  "files": [
    {
      "file": "synthetic-with-gps.jpg",
      "bytes": 34634,
      "dimensions_px": [
        1200,
        840
      ],
      "exif_tags": {
        "272": "No real camera",
        "306": "2026:10:29 09:00:00",
        "271": "Synthetic Test"
      },
      "gps_ifd": {
        "1": "N",
        "2": "(0.0, 0.0, 0.0)",
        "3": "E",
        "4": "(0.0, 0.0, 0.0)"
      },
      "decoded_rgb_sha256": "4247892df8bb22dd80fc542f0ee142e42de7dbfb36256f3b36b6069508e2eb54",
      "sha256": "451cb7aa32835764889493a4e09e8b4ba440fa5ce81125468abd1ba31f06dfa3"
    },
    {
      "file": "synthetic-reencoded-without-exif.jpg",
      "bytes": 36437,
      "dimensions_px": [
        1200,
        840
      ],
      "exif_tags": {},
      "gps_ifd": {},
      "decoded_rgb_sha256": "a29b9b6546a58f665f314790e810d91e71522518270b4e06a211a0761ba70fde",
      "sha256": "b006db0ca3b4ec80544f0a9317f85f89f26072d43da9d1ed7b51b86a09c8e373"
    }
  ],
  "observations": {
    "dimensions_preserved": true,
    "gps_removed_in_reencoded_output": true,
    "camera_and_datetime_tags_removed": true,
    "decoded_pixel_hash_equal": false,
    "interpretation": "This demonstrates behavior for these locally generated files and this Pillow re-encode only. It does not show whether MyERAS, MyIntealth, or another service strips, stores, exposes, or preserves metadata. Re-encoding JPEG can alter decoded pixels even when dimensions remain the same."
  }
}