image-label: JSON schemas and clarifications

0.4/examples/label_strict/.config.json

@@ -0,0 +1,3 @@
+{
+    "schema": "schemas/strict_label.schema"
+}

0.4/examples/label_strict/colors_properties.json

@@ -0,0 +1,29 @@
+{
+  "image-label": {
+    "version": "0.4",
+    "colors": [
+      {
+        "label-value": 1,
+        "rgba": [255, 255, 255, 255]
+      },
+      {
+        "label-value": 4,
+        "rgba": [0, 255, 255, 128]
+      }
+    ],
+    "properties": [
+      {
+        "label-value": 1,
+        "area (pixels)": 1200,
+        "class": "foo"
+      },
+      {
+        "label-value": 4,
+        "area (pixels)": 1650
+      }
+    ],
+    "source": {
+      "image": "../../"
+    }
+  }
+}

0.4/index.bs

@@ -375,63 +375,37 @@ in which each unique pixel value represents a separate segmented object.
 `image-label` groups MUST also contain `multiscales` metadata and the two
 "datasets" series MUST have the same number of entries.
 
-The `colors` key defines a list of JSON objects describing the unique label
-values. Each entry in the list MUST contain the key "label-value" with the
-pixel value for that label. Additionally, the "rgba" key MAY be present, the
-value for which is an RGBA unsigned-int 4-tuple: `[uint8, uint8, uint8, uint8]`
-All `label-value`s must be unique. Clients who choose to not throw an error
-should ignore all except the _last_ entry.
-
-Some implementations may represent overlapping labels by using a specially assigned
+The `image-label` dictionary SHOULD contain a `colors` key whose value MUST be a
+list of JSON objects describing the unique label values. Each color object MUST
+contain the `label-value` key whose value MUST be an integer specifying the
+pixel value for that label. It MAY contain an `rgba` key whose value MUST be an array
+of four integers between 0 and 255 `[uint8, uint8, uint8, uint8]` specifying the label
+color as RGBA. All the values under the `label-value` key MUST be unique. Clients
+who choose to not throw an error SHOULD ignore all except the _last_ entry.
+
+Some implementations MAY represent overlapping labels by using a specially assigned
 value, for example the highest integer available in the pixel range.
 
-The `properties` key defines a list of JSON objects which also describes the unique
-label values. Each entry in the list MUST contain the key "label-value" with the
-pixel value for that label. Additionally, an arbitrary number of key-value pairs
+The `image-label` dictionary MAY contain a `properties` key whose value MUST be a
+list of JSON objects which also describes the unique label values. Each property object
+MUST contain the `label-value` key whose value MUST be an integer specifying the pixel
+value for that label. Additionally, an arbitrary number of key-value pairs
 MAY be present for each label value denoting associated metadata. Not all label
 values must share the same key-value pairs within the properties list.
 
-The `source` key is an optional dictionary which contains information on the
-image the label is associated with. If included it MAY include a key `image`
-whose value is the relative path to a Zarr image group. The default value is
-"../../" since most labels are stored under a subgroup named "labels/" (see
-above).
+The `image-label` dictionary MAY contain a `source` key whose value MUST be a JSON
+object containing information on the image the label is associated with. If included,
+it MAY include a key `image` whose value MUST be a string specifying the relative
+path to a Zarr image group. The default value is "../../" since most labels are stored
+under a subgroup named "labels/" (see above).
 
+The `image-label` dictionary SHOULD contain a `version` key whose value MUST be a string
+specifying the version of the image-label specification.
 
-```json
-"image-label":
-  {
-    "version": "0.4",
-    "colors": [
-      {
-        "label-value": 1,
-        "rgba": [255, 255, 255, 0]
-      },
-      {
-        "label-value": 4,
-        "rgba": [0, 255, 255, 128]
-      },
-      ...
-      ],
-    "properties": [
-      {
-        "label-value": 1,
-        "area (pixels)": 1200,
-        "class": "foo"
-
-      },
-      {
-        "label-value": 4,
-        "area (pixels)": 1650
-      },
-      ...
-      ]
-  },
-  "source": {
-    "image": "../../"
-  }
-]
-```
+<pre class=include-code>
+path: examples/label_strict/colors_properties.json
+highlight: json
+</pre>
 
 "plate" metadata {#plate-md}
 ----------------------------

0.4/schemas/label.schema

@@ -0,0 +1,77 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://ngff.openmicroscopy.org/0.4/schemas/label.schema",
+  "title": "OME-NGFF labelled image schema",
+  "description": "JSON from OME-NGFF .zattrs",
+  "type": "object",
+  "properties": {
+    "image-label": {
+      "type": "object",
+      "properties": {
+        "colors": {
+          "description": "The colors for this label image",
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "label-value": {
+                "description": "The value of the label",
+                "type": "number"
+              },
+              "rgba": {
+                "description": "The RGBA color stored as an array of four integers between 0 and 255",
+                "type": "array",
+                "items": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "maximum": 255
+                },
+                "minItems": 4,
+                "maxItems": 4
+              }
+            },
+            "required": [
+              "label-value"
+            ]
+          },
+          "minItems": 1,
+          "uniqueItems": true
+        },
+        "properties": {
+          "description": "The properties for this label image",
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "label-value": {
+                "description": "The pixel value for this label",
+                "type": "integer"
+              }
+            },
+            "required": [
+              "label-value"
+            ]
+          },
+          "minItems": 1,
+          "uniqueItems": true
+        },
+        "source": {
+          "description": "The source of this label image",
+          "type": "object",
+          "properties": {
+            "image": {
+              "type": "string"
+            }
+          }
+        },
+        "version": {
+          "description": "The version of the specification",
+          "type": "string",
+          "enum": [
+            "0.4"
+          ]
+        }
+      }
+    }
+  }
+}

0.4/schemas/strict_label.schema

@@ -0,0 +1,18 @@
+{
+  "$id": "https://ngff.openmicroscopy.org/0.4/schemas/strict_label.schema",
+  "allOf": [
+    {
+      "$ref": "https://ngff.openmicroscopy.org/0.4/schemas/label.schema"
+    },
+    {
+      "properties": {
+        "image-label": {
+          "required": [
+            "version",
+            "colors"
+          ]
+        }
+      }
+    }
+  ]
+}

0.4/tests/label_suite.json

@@ -0,0 +1,131 @@
+{
+  "description": "Tests for the image-label JSON schema",
+  "schema": {
+    "id": "schemas/label.schema"
+  },
+  "tests": [
+    {
+      "formerly": "image-label/minimal",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 0]
+            }
+          ]
+        }
+      },
+      "valid": true
+    },
+    {
+      "formerly": "image-label/minimal_properties",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 0]
+            }
+          ],
+          "properties": [
+            {
+              "label-value": 1
+            }
+          ]
+        }
+      },
+      "valid": true
+    },
+    {
+      "formerly": "image-label/empty_colors",
+      "data": {
+        "image-label": {
+          "colors": []
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/empty_properties",
+      "data": {
+        "image-label": {
+          "properties": []
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/colors_no_label_value",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "rgba": [0, 0, 0, 0]
+            }
+          ]
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/properties_no_label_value",
+      "data": {
+        "image-label": {
+          "properties": [
+            {
+              "value": "foo"
+            }
+          ]
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/colors_rgba_length",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0]
+            }
+          ]
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/colors_rgba_type",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 500]
+            }
+          ]
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/colors_duplicate",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 0]
+            },
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 0]
+            }
+          ]
+        }
+      },
+      "valid": false
+    }
+  ]
+}

0.4/tests/strict_label_suite.json

@@ -0,0 +1,31 @@
+{
+  "description": "Tests for the strict image-label JSON schema",
+  "schema": {
+    "id": "schemas/strict_label.schema"
+  },
+  "tests": [
+    {
+      "formerly": "image-label/no_version",
+      "data": {
+        "image-label": {
+          "colors": [
+            {
+              "label-value": 1,
+              "rgba": [0, 0, 0, 0]
+            }
+          ]
+        }
+      },
+      "valid": false
+    },
+    {
+      "formerly": "image-label/no_colors",
+      "data": {
+        "image-label": {
+          "version": "0.4"
+        }
+      },
+      "valid": false
+    }
+  ]
+}

latest/examples/label_strict/.config.json

@@ -0,0 +1,3 @@
+{
+    "schema": "schemas/strict_label.schema"
+}