madoo.image-statistics/v1

Madoo image statistics — Tone and colour of an image, of grid cells or regions, optionally inside a mask: luma quantiles, near-black and near-white shares, luminance, Oklab means, colour per tone band (Image Statistics).


Reference	`madoo.image-statistics/v1`
Schema id	`urn:madoo:schema:image-statistics:v1`
Version	1.0.0
Served at	`GET /api/v1/json-schemas/madoo.image-statistics/v1` · MCP `get_json_schema`

Where it appears

Produced by: image/statistics → statistics

Fields

for a grid cell (1-based), or the id given with the region.for a grid cell (1-based), or the id given with the region.

Field	Type	Required	Rules	Description
`schema`	`"madoo.image-statistics/v1"`	yes
`algorithm_version`	string	yes
`image`	object	yes
`image.width`	integer	yes	≥ 1	After EXIF orientation.
`image.height`	integer	yes	≥ 1
`image.orientation_applied`	boolean	yes		True when the EXIF orientation rotated or mirrored the image.
`color`	object	yes
`color.working_space`	`"srgb-8"`	yes
`color.profile_policy`	one of `"srgb"`, `"converted"`, `"assumed_srgb"`	yes		srgb: the file is sRGB; converted: its ICC profile was converted to sRGB; assumed_srgb: an RGB image without a profile, read as sRGB.
`color.source_depth`	integer or null	yes		Bits per channel of the file.
`color.analysis_depth`	`8`	yes
`warnings`	array of string	yes		Facts that limit how the numbers may be read: a JPEG source (compression can contaminate detail measurements), several frames or pages (the first was measured), a source deeper than 8 bits (measured at 8 bits).
`settings`	object	yes
`settings.grid`	object or null
`settings.grid.rows`	integer
`settings.grid.cols`	integer
`settings.alpha_min`	integer	yes	≥ 0; ≤ 255
`settings.mask`	boolean	yes
`settings.mask_threshold`	integer or null
`settings.max_samples`	integer	yes	≥ 1
`settings.bands`	array of number	yes	min items 2
`settings.near_black`	number	yes
`settings.near_white`	number	yes
`global`	object	yes
`global.index`	integer	yes	≥ 0	0 for the global region, then 1..n in reading order.
`global.id`	string	yes		global, rc
`global.cell`	object	yes		Pixels of the oriented image, origin top left; covers columns x..x+width-1 and rows y..y+height-1.
`global.cell.x`	integer	yes	≥ 0
`global.cell.y`	integer	yes	≥ 0
`global.cell.width`	integer	yes	≥ 1
`global.cell.height`	integer	yes	≥ 1
`global.mask_share`	number or null		≥ 0; ≤ 1	Share of the region inside the mask; present only when a mask is connected.
`global.sampling`	object	yes
`global.sampling.method`	one of `"grid"`, `"full"`	yes
`global.sampling.step`	integer	yes	≥ 1
`global.sampling.eligible_pixels`	integer	yes	≥ 0	Pixels of the region that may be measured: opaque enough and inside the mask.
`global.sampling.sampled_pixels`	integer	yes	≥ 0
`global.status`	one of `"ok"`, `"not_observable"`	yes		not_observable: the measurement is undefined here (see reason); its numbers are null. Zero is a valid measurement, never a stand-in for null.
`global.reason`	one of `null`, `"no_eligible_pixels"`, `"too_few_samples"`, `"zero_variance"`, `"no_eligible_patches"`, `"mask_empty_in_region"`	yes
`global.luma`	object	yes		Y’ Rec.709 on encoded sRGB, 0.2126 R’ + 0.7152 G’ + 0.0722 B’, in [0, 1]. Quantile p = the sorted value at index floor((N-1)p), no interpolation.
`global.luma.p01`	number or null		≥ 0; ≤ 1
`global.luma.p05`	number or null		≥ 0; ≤ 1
`global.luma.p25`	number or null		≥ 0; ≤ 1
`global.luma.p50`	number or null		≥ 0; ≤ 1
`global.luma.p75`	number or null		≥ 0; ≤ 1
`global.luma.p95`	number or null		≥ 0; ≤ 1
`global.luma.p99`	number or null		≥ 0; ≤ 1
`global.luma.mean`	number or null		≥ 0; ≤ 1
`global.luma.near_black_share`	number or null		≥ 0; ≤ 1	Share of sampled pixels with luma <= near_black.
`global.luma.near_white_share`	number or null		≥ 0; ≤ 1	Share of sampled pixels with luma >= near_white.
`global.luminance`	object	yes		Y Rec.709 on linearized sRGB (relative luminance), in [0, 1].
`global.luminance.mean`	number or null		≥ 0; ≤ 1
`global.luminance.p50`	number or null		≥ 0; ≤ 1
`global.oklab`	object	yes
`global.oklab.mean_l`	number or null
`global.oklab.mean_a`	number or null
`global.oklab.mean_b`	number or null
`global.bands`	array of objects	yes		One entry per Oklab L band set by the bands parameter, in increasing order.
`global.bands[].l_min`	number	yes
`global.bands[].l_max`	number	yes		Exclusive, except for the last band.
`global.bands[].n`	integer	yes	≥ 0
`global.bands[].share`	number or null	yes	≥ 0; ≤ 1	n divided by the sampled pixels of the region.
`global.bands[].chroma`	object			Oklab chroma quantiles of the band (same rule as luma).
`global.bands[].chroma.p01`	number or null
`global.bands[].chroma.p05`	number or null
`global.bands[].chroma.p25`	number or null
`global.bands[].chroma.p50`	number or null
`global.bands[].chroma.p75`	number or null
`global.bands[].chroma.p95`	number or null
`global.bands[].chroma.p99`	number or null
`global.bands[].neutral_n`	integer		≥ 0	Pixels with chroma < 0.06.
`global.bands[].neutral_a_p50`	number or null			Median a of the neutral pixels; null when there are none.
`global.bands[].neutral_b_p50`	number or null
`global.bands[].hue_bins`	array of objects		min items 12; max items 12	The pixels with chroma >= 0.03 by hue atan2(b, a), bin k covering [30k, 30(k+1)) degrees. Neutral (chroma < 0.06) and hue samples overlap on purpose.
`global.bands[].hue_bins[].start`	integer	yes	≥ 0; ≤ 330
`global.bands[].hue_bins[].count`	integer	yes	≥ 0
`global.bands[].hue_bins[].share`	number or null	yes	≥ 0; ≤ 1	count divided by the pixels of the band.
`global.bands[].hue_bins[].chroma_p50`	number or null	yes		null when count is 0.
`regions`	array of objects	yes	max items 256
`regions[].index`	integer	yes	≥ 0	0 for the global region, then 1..n in reading order.
`regions[].id`	string	yes		global, rc
`regions[].cell`	object	yes		Pixels of the oriented image, origin top left; covers columns x..x+width-1 and rows y..y+height-1.
`regions[].cell.x`	integer	yes	≥ 0
`regions[].cell.y`	integer	yes	≥ 0
`regions[].cell.width`	integer	yes	≥ 1
`regions[].cell.height`	integer	yes	≥ 1
`regions[].mask_share`	number or null		≥ 0; ≤ 1	Share of the region inside the mask; present only when a mask is connected.
`regions[].sampling`	object	yes
`regions[].sampling.method`	one of `"grid"`, `"full"`	yes
`regions[].sampling.step`	integer	yes	≥ 1
`regions[].sampling.eligible_pixels`	integer	yes	≥ 0	Pixels of the region that may be measured: opaque enough and inside the mask.
`regions[].sampling.sampled_pixels`	integer	yes	≥ 0
`regions[].status`	one of `"ok"`, `"not_observable"`	yes		not_observable: the measurement is undefined here (see reason); its numbers are null. Zero is a valid measurement, never a stand-in for null.
`regions[].reason`	one of `null`, `"no_eligible_pixels"`, `"too_few_samples"`, `"zero_variance"`, `"no_eligible_patches"`, `"mask_empty_in_region"`	yes
`regions[].luma`	object	yes		Y’ Rec.709 on encoded sRGB, 0.2126 R’ + 0.7152 G’ + 0.0722 B’, in [0, 1]. Quantile p = the sorted value at index floor((N-1)p), no interpolation.
`regions[].luma.p01`	number or null		≥ 0; ≤ 1
`regions[].luma.p05`	number or null		≥ 0; ≤ 1
`regions[].luma.p25`	number or null		≥ 0; ≤ 1
`regions[].luma.p50`	number or null		≥ 0; ≤ 1
`regions[].luma.p75`	number or null		≥ 0; ≤ 1
`regions[].luma.p95`	number or null		≥ 0; ≤ 1
`regions[].luma.p99`	number or null		≥ 0; ≤ 1
`regions[].luma.mean`	number or null		≥ 0; ≤ 1
`regions[].luma.near_black_share`	number or null		≥ 0; ≤ 1	Share of sampled pixels with luma <= near_black.
`regions[].luma.near_white_share`	number or null		≥ 0; ≤ 1	Share of sampled pixels with luma >= near_white.
`regions[].luminance`	object	yes		Y Rec.709 on linearized sRGB (relative luminance), in [0, 1].
`regions[].luminance.mean`	number or null		≥ 0; ≤ 1
`regions[].luminance.p50`	number or null		≥ 0; ≤ 1
`regions[].oklab`	object	yes
`regions[].oklab.mean_l`	number or null
`regions[].oklab.mean_a`	number or null
`regions[].oklab.mean_b`	number or null
`regions[].bands`	array of objects	yes		One entry per Oklab L band set by the bands parameter, in increasing order.
`regions[].bands[].l_min`	number	yes
`regions[].bands[].l_max`	number	yes		Exclusive, except for the last band.
`regions[].bands[].n`	integer	yes	≥ 0
`regions[].bands[].share`	number or null	yes	≥ 0; ≤ 1	n divided by the sampled pixels of the region.
`regions[].bands[].chroma`	object			Oklab chroma quantiles of the band (same rule as luma).
`regions[].bands[].chroma.p01`	number or null
`regions[].bands[].chroma.p05`	number or null
`regions[].bands[].chroma.p25`	number or null
`regions[].bands[].chroma.p50`	number or null
`regions[].bands[].chroma.p75`	number or null
`regions[].bands[].chroma.p95`	number or null
`regions[].bands[].chroma.p99`	number or null
`regions[].bands[].neutral_n`	integer		≥ 0	Pixels with chroma < 0.06.
`regions[].bands[].neutral_a_p50`	number or null			Median a of the neutral pixels; null when there are none.
`regions[].bands[].neutral_b_p50`	number or null
`regions[].bands[].hue_bins`	array of objects		min items 12; max items 12	The pixels with chroma >= 0.03 by hue atan2(b, a), bin k covering [30k, 30(k+1)) degrees. Neutral (chroma < 0.06) and hue samples overlap on purpose.
`regions[].bands[].hue_bins[].start`	integer	yes	≥ 0; ≤ 330
`regions[].bands[].hue_bins[].count`	integer	yes	≥ 0
`regions[].bands[].hue_bins[].share`	number or null	yes	≥ 0; ≤ 1	count divided by the pixels of the band.
`regions[].bands[].hue_bins[].chroma_p50`	number or null	yes		null when count is 0.

The complete schema

madoo.image-statistics/v1 (JSON Schema)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:madoo:schema:image-statistics:v1",
  "title": "Madoo image statistics",
  "description": "What Image Statistics (image/statistics) measured: tone and colour of the whole image and of each region (grid cell, given rectangle), optionally only inside a mask. Deterministic for the same image, algorithm_version and settings.",
  "type": "object",
  "required": [
    "schema",
    "algorithm_version",
    "image",
    "color",
    "warnings",
    "settings",
    "global",
    "regions"
  ],
  "properties": {
    "schema": {
      "const": "madoo.image-statistics/v1"
    },
    "algorithm_version": {
      "type": "string"
    },
    "image": {
      "$ref": "#/$defs/image"
    },
    "color": {
      "$ref": "#/$defs/color"
    },
    "warnings": {
      "$ref": "#/$defs/warnings"
    },
    "settings": {
      "type": "object",
      "required": [
        "alpha_min",
        "max_samples",
        "bands",
        "near_black",
        "near_white",
        "mask"
      ],
      "properties": {
        "grid": {
          "type": [
            "object",
            "null"
          ],
          "properties": {
            "rows": {
              "type": "integer"
            },
            "cols": {
              "type": "integer"
            }
          }
        },
        "alpha_min": {
          "type": "integer",
          "minimum": 0,
          "maximum": 255
        },
        "mask": {
          "type": "boolean"
        },
        "mask_threshold": {
          "type": [
            "integer",
            "null"
          ]
        },
        "max_samples": {
          "type": "integer",
          "minimum": 1
        },
        "bands": {
          "type": "array",
          "items": {
            "type": "number"
          },
          "minItems": 2
        },
        "near_black": {
          "type": "number"
        },
        "near_white": {
          "type": "number"
        }
      }
    },
    "global": {
      "type": "object",
      "required": [
        "index",
        "id",
        "cell",
        "sampling",
        "status",
        "reason",
        "luma",
        "luminance",
        "oklab",
        "bands"
      ],
      "properties": {
        "index": {
          "type": "integer",
          "minimum": 0,
          "description": "0 for the global region, then 1..n in reading order."
        },
        "id": {
          "type": "string",
          "description": "global, r<row>c<col> for a grid cell (1-based), or the id given with the region."
        },
        "cell": {
          "$ref": "#/$defs/rect"
        },
        "mask_share": {
          "type": [
            "number",
            "null"
          ],
          "minimum": 0,
          "maximum": 1,
          "description": "Share of the region inside the mask; present only when a mask is connected."
        },
        "sampling": {
          "$ref": "#/$defs/sampling"
        },
        "status": {
          "$ref": "#/$defs/status"
        },
        "reason": {
          "$ref": "#/$defs/reason"
        },
        "luma": {
          "type": "object",
          "description": "Y' Rec.709 on encoded sRGB, 0.2126 R' + 0.7152 G' + 0.0722 B', in [0, 1]. Quantile p = the sorted value at index floor((N-1)p), no interpolation.",
          "properties": {
            "p01": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p05": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p25": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p50": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p75": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p95": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p99": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "mean": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "near_black_share": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1,
              "description": "Share of sampled pixels with luma <= near_black."
            },
            "near_white_share": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1,
              "description": "Share of sampled pixels with luma >= near_white."
            }
          }
        },
        "luminance": {
          "type": "object",
          "description": "Y Rec.709 on linearized sRGB (relative luminance), in [0, 1].",
          "properties": {
            "mean": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            },
            "p50": {
              "type": [
                "number",
                "null"
              ],
              "minimum": 0,
              "maximum": 1
            }
          }
        },
        "oklab": {
          "type": "object",
          "properties": {
            "mean_l": {
              "type": [
                "number",
                "null"
              ]
            },
            "mean_a": {
              "type": [
                "number",
                "null"
              ]
            },
            "mean_b": {
              "type": [
                "number",
                "null"
              ]
            }
          }
        },
        "bands": {
          "type": "array",
          "description": "One entry per Oklab L band set by the bands parameter, in increasing order.",
          "items": {
            "type": "object",
            "required": [
              "l_min",
              "l_max",
              "n",
              "share"
            ],
            "properties": {
              "l_min": {
                "type": "number"
              },
              "l_max": {
                "type": "number",
                "description": "Exclusive, except for the last band."
              },
              "n": {
                "type": "integer",
                "minimum": 0
              },
              "share": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1,
                "description": "n divided by the sampled pixels of the region."
              },
              "chroma": {
                "type": "object",
                "description": "Oklab chroma quantiles of the band (same rule as luma).",
                "properties": {
                  "p01": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p05": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p25": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p50": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p75": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p95": {
                    "type": [
                      "number",
                      "null"
                    ]
                  },
                  "p99": {
                    "type": [
                      "number",
                      "null"
                    ]
                  }
                }
              },
              "neutral_n": {
                "type": "integer",
                "minimum": 0,
                "description": "Pixels with chroma < 0.06."
              },
              "neutral_a_p50": {
                "type": [
                  "number",
                  "null"
                ],
                "description": "Median a of the neutral pixels; null when there are none."
              },
              "neutral_b_p50": {
                "type": [
                  "number",
                  "null"
                ]
              },
              "hue_bins": {
                "type": "array",
                "minItems": 12,
                "maxItems": 12,
                "description": "The pixels with chroma >= 0.03 by hue atan2(b, a), bin k covering [30k, 30(k+1)) degrees. Neutral (chroma < 0.06) and hue samples overlap on purpose.",
                "items": {
                  "type": "object",
                  "required": [
                    "start",
                    "count",
                    "share",
                    "chroma_p50"
                  ],
                  "properties": {
                    "start": {
                      "type": "integer",
                      "minimum": 0,
                      "maximum": 330
                    },
                    "count": {
                      "type": "integer",
                      "minimum": 0
                    },
                    "share": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "minimum": 0,
                      "maximum": 1,
                      "description": "count divided by the pixels of the band."
                    },
                    "chroma_p50": {
                      "type": [
                        "number",
                        "null"
                      ],
                      "description": "null when count is 0."
                    }
                  }
                }
              }
            }
          }
        }
      }
    },
    "regions": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "index",
          "id",
          "cell",
          "sampling",
          "status",
          "reason",
          "luma",
          "luminance",
          "oklab",
          "bands"
        ],
        "properties": {
          "index": {
            "type": "integer",
            "minimum": 0,
            "description": "0 for the global region, then 1..n in reading order."
          },
          "id": {
            "type": "string",
            "description": "global, r<row>c<col> for a grid cell (1-based), or the id given with the region."
          },
          "cell": {
            "$ref": "#/$defs/rect"
          },
          "mask_share": {
            "type": [
              "number",
              "null"
            ],
            "minimum": 0,
            "maximum": 1,
            "description": "Share of the region inside the mask; present only when a mask is connected."
          },
          "sampling": {
            "$ref": "#/$defs/sampling"
          },
          "status": {
            "$ref": "#/$defs/status"
          },
          "reason": {
            "$ref": "#/$defs/reason"
          },
          "luma": {
            "type": "object",
            "description": "Y' Rec.709 on encoded sRGB, 0.2126 R' + 0.7152 G' + 0.0722 B', in [0, 1]. Quantile p = the sorted value at index floor((N-1)p), no interpolation.",
            "properties": {
              "p01": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p05": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p25": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p50": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p75": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p95": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p99": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "mean": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "near_black_share": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1,
                "description": "Share of sampled pixels with luma <= near_black."
              },
              "near_white_share": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1,
                "description": "Share of sampled pixels with luma >= near_white."
              }
            }
          },
          "luminance": {
            "type": "object",
            "description": "Y Rec.709 on linearized sRGB (relative luminance), in [0, 1].",
            "properties": {
              "mean": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              },
              "p50": {
                "type": [
                  "number",
                  "null"
                ],
                "minimum": 0,
                "maximum": 1
              }
            }
          },
          "oklab": {
            "type": "object",
            "properties": {
              "mean_l": {
                "type": [
                  "number",
                  "null"
                ]
              },
              "mean_a": {
                "type": [
                  "number",
                  "null"
                ]
              },
              "mean_b": {
                "type": [
                  "number",
                  "null"
                ]
              }
            }
          },
          "bands": {
            "type": "array",
            "description": "One entry per Oklab L band set by the bands parameter, in increasing order.",
            "items": {
              "type": "object",
              "required": [
                "l_min",
                "l_max",
                "n",
                "share"
              ],
              "properties": {
                "l_min": {
                  "type": "number"
                },
                "l_max": {
                  "type": "number",
                  "description": "Exclusive, except for the last band."
                },
                "n": {
                  "type": "integer",
                  "minimum": 0
                },
                "share": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "minimum": 0,
                  "maximum": 1,
                  "description": "n divided by the sampled pixels of the region."
                },
                "chroma": {
                  "type": "object",
                  "description": "Oklab chroma quantiles of the band (same rule as luma).",
                  "properties": {
                    "p01": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p05": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p25": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p50": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p75": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p95": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "p99": {
                      "type": [
                        "number",
                        "null"
                      ]
                    }
                  }
                },
                "neutral_n": {
                  "type": "integer",
                  "minimum": 0,
                  "description": "Pixels with chroma < 0.06."
                },
                "neutral_a_p50": {
                  "type": [
                    "number",
                    "null"
                  ],
                  "description": "Median a of the neutral pixels; null when there are none."
                },
                "neutral_b_p50": {
                  "type": [
                    "number",
                    "null"
                  ]
                },
                "hue_bins": {
                  "type": "array",
                  "minItems": 12,
                  "maxItems": 12,
                  "description": "The pixels with chroma >= 0.03 by hue atan2(b, a), bin k covering [30k, 30(k+1)) degrees. Neutral (chroma < 0.06) and hue samples overlap on purpose.",
                  "items": {
                    "type": "object",
                    "required": [
                      "start",
                      "count",
                      "share",
                      "chroma_p50"
                    ],
                    "properties": {
                      "start": {
                        "type": "integer",
                        "minimum": 0,
                        "maximum": 330
                      },
                      "count": {
                        "type": "integer",
                        "minimum": 0
                      },
                      "share": {
                        "type": [
                          "number",
                          "null"
                        ],
                        "minimum": 0,
                        "maximum": 1,
                        "description": "count divided by the pixels of the band."
                      },
                      "chroma_p50": {
                        "type": [
                          "number",
                          "null"
                        ],
                        "description": "null when count is 0."
                      }
                    }
                  }
                }
              }
            }
          }
        }
      },
      "maxItems": 256
    }
  },
  "$defs": {
    "rect": {
      "type": "object",
      "required": [
        "x",
        "y",
        "width",
        "height"
      ],
      "properties": {
        "x": {
          "type": "integer",
          "minimum": 0
        },
        "y": {
          "type": "integer",
          "minimum": 0
        },
        "width": {
          "type": "integer",
          "minimum": 1
        },
        "height": {
          "type": "integer",
          "minimum": 1
        }
      },
      "description": "Pixels of the oriented image, origin top left; covers columns x..x+width-1 and rows y..y+height-1."
    },
    "image": {
      "type": "object",
      "required": [
        "width",
        "height",
        "orientation_applied"
      ],
      "properties": {
        "width": {
          "type": "integer",
          "minimum": 1,
          "description": "After EXIF orientation."
        },
        "height": {
          "type": "integer",
          "minimum": 1
        },
        "orientation_applied": {
          "type": "boolean",
          "description": "True when the EXIF orientation rotated or mirrored the image."
        }
      }
    },
    "color": {
      "type": "object",
      "required": [
        "working_space",
        "profile_policy",
        "source_depth",
        "analysis_depth"
      ],
      "properties": {
        "working_space": {
          "const": "srgb-8"
        },
        "profile_policy": {
          "enum": [
            "srgb",
            "converted",
            "assumed_srgb"
          ],
          "description": "srgb: the file is sRGB; converted: its ICC profile was converted to sRGB; assumed_srgb: an RGB image without a profile, read as sRGB."
        },
        "source_depth": {
          "type": [
            "integer",
            "null"
          ],
          "description": "Bits per channel of the file."
        },
        "analysis_depth": {
          "const": 8
        }
      }
    },
    "sampling": {
      "type": "object",
      "required": [
        "method",
        "step",
        "eligible_pixels",
        "sampled_pixels"
      ],
      "properties": {
        "method": {
          "enum": [
            "grid",
            "full"
          ]
        },
        "step": {
          "type": "integer",
          "minimum": 1
        },
        "eligible_pixels": {
          "type": "integer",
          "minimum": 0,
          "description": "Pixels of the region that may be measured: opaque enough and inside the mask."
        },
        "sampled_pixels": {
          "type": "integer",
          "minimum": 0
        }
      }
    },
    "warnings": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Facts that limit how the numbers may be read: a JPEG source (compression can contaminate detail measurements), several frames or pages (the first was measured), a source deeper than 8 bits (measured at 8 bits)."
    },
    "status": {
      "enum": [
        "ok",
        "not_observable"
      ],
      "description": "not_observable: the measurement is undefined here (see reason); its numbers are null. Zero is a valid measurement, never a stand-in for null."
    },
    "reason": {
      "type": [
        "string",
        "null"
      ],
      "enum": [
        null,
        "no_eligible_pixels",
        "too_few_samples",
        "zero_variance",
        "no_eligible_patches",
        "mask_empty_in_region"
      ]
    }
  }
}