Class labels

How to add label classes and define an ontology for an annotation task

You can add labels to a task when creating it. You can also add new labels to an existing task. Note that you cannot delete or edit an existing label (Unless you are adding new attributes).

If you already have the labels defined in another task, you can copy those when setting up labels for a new task. Simply select the task from which you would like to copy labels.

You can copy labels from an existing task when creating a new task

When creating a label, you can specify its Name and color, and add attributes of various types.

Label attributes

You can add multiple attributes to each label of the following types:

1. Text - Enter free-form text. This can be used for small text entries like license plates as well as for longer form entries for OCR use-cases.

2. Number - Enter a numerical value.

3. Radio button - Add multiple options from which a single value can be chosen.

4. Checkbox - True or False type value.

You can add multiple attributes of various types to each label

Further, each attribute can be marked as Mutable and Required.

1. Mutable - Only applies to Tracks. If checked, this allows the attribute values to change from frame to frame for the same object. For example, a car can be occluded or not occluded in different frames, so its Mutable property should be set to True. Other attributes however, such as License plate, type of car, color etc. are unique to the object, so their Mutable property should be set to False.

2. Required - Set this to true if you want to set a validation check to ensure the labeler has set an appropriate value to the attributes. If an annotation fails this test, it will be highlighted in red on the annotation page.

If an attribute is marked required, and it has not bee set by the labeler, it will be highlighted in red.