{
  "experiment_date_beijing": "2026-10-07",
  "generator_environment": {
    "python": "3.9.6",
    "macos": "27.0.1",
    "machine": "arm64",
    "zlib_runtime": "1.2.12",
    "dependencies": "Python standard library only"
  },
  "scope": "generated non-interlaced 8-bit RGB only; no profiles or alpha",
  "uncompressed_rgb_bytes_per_fixture": 98304,
  "filtered_scanline_bytes": 98432,
  "noise_seed": "gumi-png-size-lab-noise-v1",
  "sub_row_examples": [
    {
      "original": [
        100,
        150,
        200,
        101,
        151,
        201
      ],
      "filtered": [
        100,
        150,
        200,
        1,
        1,
        1
      ]
    },
    {
      "original": [
        250,
        251,
        255,
        2,
        3,
        4
      ],
      "filtered": [
        250,
        251,
        255,
        8,
        8,
        5
      ]
    }
  ],
  "records": [
    {
      "file": "gradient-none-0.png",
      "fixture": "gradient",
      "filter": "none",
      "level": 0,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 98505,
      "file_sha256": "ffcded730baa02f56aaa0c28703419d69d320c76e23a479914c6c21b9557d7e0",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 98448
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 98448,
      "idat_sha256": "42e9500a994b8f2e64818f789d5b10a5bba0c6bc7143d9ad5b6cba12780a76a2",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "gradient-none-9.png",
      "fixture": "gradient",
      "filter": "none",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 93425,
      "file_sha256": "8e13a142ca55761d727c8c0c6d5c28549b3a7dfebdf21ff22f5854424b3bf3d4",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 93368
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 93368,
      "idat_sha256": "3ab36b6807af627fa63bfca5d866f4ec89cb6eba3edeb9a9ed47418f3e647a69",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "gradient-sub-9.png",
      "fixture": "gradient",
      "filter": "sub",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 726,
      "file_sha256": "8d7781a1e9bb59daf53d122b58dd5468f2fb535f841c0186c45f018402f25e0c",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 669
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 669,
      "idat_sha256": "7dcfcce63b5add26b24afb1eaff819fcac72603f07fc2d36b4591968d3919dc9",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "gradient-sub-9-text.png",
      "fixture": "gradient",
      "filter": "sub",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 4842,
      "file_sha256": "456e6b2de1eb293d9669d769fab3bceb560e54bf5598e14f02994c336ad76549",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "expect_reference_match": true,
      "text_characters": 4096,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "tEXt",
          "payload_bytes": 4104
        },
        {
          "type": "IDAT",
          "payload_bytes": 669
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 669,
      "idat_sha256": "7dcfcce63b5add26b24afb1eaff819fcac72603f07fc2d36b4591968d3919dc9",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "gradient-sub-9-split.png",
      "fixture": "gradient",
      "filter": "sub",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 1218,
      "file_sha256": "eba93aa2d0dbd4e8acad8fd1a5e0c5d06b2c98ec0a28acb7bef037f4ae0da8ca",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 16
        },
        {
          "type": "IDAT",
          "payload_bytes": 13
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 42,
      "idat_payload_bytes": 669,
      "idat_sha256": "7dcfcce63b5add26b24afb1eaff819fcac72603f07fc2d36b4591968d3919dc9",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "noise-none-9.png",
      "fixture": "noise",
      "filter": "none",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 98530,
      "file_sha256": "51fb21687c84a56b0ff2baceddfdb2f9adddf96fe1ac8cbb5473e9bf0d23f5cf",
      "reference_rgb_sha256": "c10438e7cef15bbc42f6de232504df197de383c00b88e96d613ff4a672adb871",
      "encoded_rgb_sha256": "c10438e7cef15bbc42f6de232504df197de383c00b88e96d613ff4a672adb871",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 98473
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 98473,
      "idat_sha256": "177bcd5077279d1b932e549bed31d24052fd158f2a119f7641f213f75acf04dd",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "noise-sub-9.png",
      "fixture": "noise",
      "filter": "sub",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 98530,
      "file_sha256": "ce3542f0c2d7b3722acbb614aadd205ce7c39dd6e7cd2be41a4925d2290735b9",
      "reference_rgb_sha256": "c10438e7cef15bbc42f6de232504df197de383c00b88e96d613ff4a672adb871",
      "encoded_rgb_sha256": "c10438e7cef15bbc42f6de232504df197de383c00b88e96d613ff4a672adb871",
      "expect_reference_match": true,
      "text_characters": 0,
      "intentional_pixel_change": false,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 98473
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 98473,
      "idat_sha256": "ec6e012fc191befe7823de1661e9848624f6c75a811ea0c4b2379445ac9ba25e",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    },
    {
      "file": "gradient-sub-9-changed.png",
      "fixture": "gradient",
      "filter": "sub",
      "level": 9,
      "width": 256,
      "height": 128,
      "channels": 3,
      "file_bytes": 741,
      "file_sha256": "364bf734828355f344117d00c151043c69b9fe81ef229e3b7ed4aa18b31026d3",
      "reference_rgb_sha256": "7e11fd9bbb5cc72644f72a1847f0066422810e8e8df38d5c8b70aab1f785732b",
      "encoded_rgb_sha256": "befa21c4f30072e363eb857ba7830eb1d07131fa5cfd9182e6c686a739073595",
      "expect_reference_match": false,
      "text_characters": 0,
      "intentional_pixel_change": true,
      "chunks": [
        {
          "type": "IHDR",
          "payload_bytes": 13
        },
        {
          "type": "IDAT",
          "payload_bytes": 684
        },
        {
          "type": "IEND",
          "payload_bytes": 0
        }
      ],
      "idat_count": 1,
      "idat_payload_bytes": 684,
      "idat_sha256": "298eee52abf1f3cefdce23df79321aa926ef1d45ee1ad0770d21931664de7c16",
      "chunk_crcs_checked": true,
      "filtered_bytes_round_trip": true
    }
  ]
}
