Linked Attributes

Each key-value defining a linked attribute should have the following structure:

  • key: a short string that serves as the identifier for the attribute
  • value: an object that should have the following keys:
    • description: a human-readable string describing the attribute to a labeler.
    • allowed_labels: a list of strings corresponding to the potential label choices this object can be linked to. If using Label Nesting, the strings in allowed_labels need to be the final "leaf" nodes.
    • type: linked
    • required: For 2d image and video annotation tasks, a boolean value representing whether this attribute is required to be annotated. Defaults to false. Note that for 3d Sensor Fusion Tasks, this option is not supported. For Sensor Fusion tasks, specifying a linked attribute will require an object to be linked before a task can be returned to you.
    • conditions (optional): a JSON that describes the conditions under which this attribute should be collected. See Conditionality for more details.

If the linked attribute is used in labeling, the value of the attribute will be the annotation UUID of the object it was linked to. If the linked attribute is not used, the linked key will not be included in the response at all.

{
  ...
  "annotation_attributes": {
    "example_linked_attribute": {
      "type": "linked",
      "description": "What is this object connected to?",
      "allowed_labels": [
        "Truck",
        "Car"
      ],
      "required": true
    }
  }
 ...
}
// This example shows two polygons representing friends. 
// The first has no linked friends. The second example is linked to the first. 

{
  "annotations": [
    {
      "label": "Friend",
      "uuid": "a6092706-266d-4de1-8a14-fa6c682a57ea",
      "vertices": [
        {
          "x": 360.73736572265625,
          "y": 200.52745056152344
        },
        {
          "x": 365.7757263183594,
          "y": 348.65576171875
        },
        {
          "x": 510.88104248046875,
          "y": 295.24896240234375
        },
        {
          "x": 468.55865478515625,
          "y": 176.34324645996094
        }
      ],
      "geometry": "polygon"
    },
    {
      "label": "Friend",
      "attributes": {
        "friend": "a6092706-266d-4de1-8a14-fa6c682a57ea"
      },
      "uuid": "c6e00dc4-a3c0-4d48-9203-8f02d9c76328",
      "vertices": [
        {
          "x": 619.7100219726562,
          "y": 166.2664794921875
        },
        {
          "x": 443.36676025390625,
          "y": 255.94961547851562
        },
        {
          "x": 507.8580017089844,
          "y": 367.8016052246094
        },
        {
          "x": 693.2703247070312,
          "y": 313.3871154785156
        }
      ],
      "geometry": "polygon"
    }
  ]
}