Thing > Annotation > Region > Polygon
| Definition | A polygon in an image or video. This is a two-dimensional object so if this occurs in a video it will be anchored to a particular frame or time point in the video. | 
| URI | http://mmif.clams.ai/vocabulary/Polygon/v4 | 
Metadata
Metadata from Region
| Property | Type | Description | 
|---|---|---|
| timeUnit | String | Specifies which unit of time the measurement is based. Can be *seconds* or *milliseconds*, or in case of annotations on a VideoDocument, *frames*. | 
Metadata from Annotation
| Property | Type | Description | 
|---|---|---|
| document | ID | The identifier of the document that the annotation is over. This has to be defined either at the metadata level, in which case it has scope over all annotations of the same type in a view, or at the instance level, in which it has scope over just the single annotation. | 
| labelset | List of Strings | When an annotation object contains results of a classification task, this metadata is used to specify the label values used in classification. Individual annotations then must have labelproperty that is one of the values in this list.[Note] Annotations from a classifier app must have this metadata or  labelsetUri metadata.[Note] Not all of labels specified in the labelsetmust occur in the output annotations. For  example, alabelsetcan contain a catch-all negative label, but if the negative label can be not interesting enough to keep in  the output annotation. | 
| labelsetUri | String | A URI to an externally defined labelset. Since the labelsetmetadata is a list of simple strings, this URI can be used to point to a more detailed definition of the labelset. This can be a JSON-LD document or a SKOS concept scheme, for example.[Note] Annotations from a classifier app must have this metadata or  labelset metadata. | 
Properties
| Property | Type | Description | 
|---|---|---|
| coordinates | List of pairs | The coordinates of the polygon, taking the top-left of the image as the origin (0,0). Unit used to measure the distance is the number of pixels. [Required] | 
| timePoint | Integer | If on a video stream, the TimePoint that the BoundingBox occurs in. | 
Properties from Annotation
| Property | Type | Description | 
|---|---|---|
| document | ID | The identifier of the document that the annotation is over. | 
| label | String | A label given to this object by a classifier. The value must be a simple  string value of the label and must be one of the values defined in the labelsetorlabelsetUriannotation metadata.[Note] Annotations from a classifier app must have this property. | 
| classifications | Map from String to Number | Alias for the classificationmetadata. Here for historical reasons. | 
| classification | Map from String to Number | A map from label values to their "score" numbers provided by a classifier. The score can be probability, similarity, confidence, or any other real  number that was used to determine the label value. [Optional] on top of the labelproperty. However when this  property is used, thelabelproperty must be one of the keys and the keys must match to the values defined in thelabelsetorlabelsetUriannotation metadata. | 
Properties from Thing
| Property | Type | Description | 
|---|---|---|
| id | ID | A unique identifier for the annotation or document. Uniqueness is relative to the view the annotation is in or the list of documents at the top level of a MMIF file. [Required] |