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Gets the label detection results of a Amazon Rekognition Video analysis started by StartLabelDetection.
The label detection operation is started by a call to StartLabelDetection which
returns a job identifier (JobId
). When the label detection operation finishes,
Amazon Rekognition publishes a completion status to the Amazon Simple Notification
Service topic registered in the initial call to StartlabelDetection
.
To get the results of the label detection operation, first check that the status value
published to the Amazon SNS topic is SUCCEEDED
. If so, call GetLabelDetection
and pass the job identifier (JobId
) from the initial call to StartLabelDetection
.
GetLabelDetection
returns an array of detected labels (Labels
) sorted
by the time the labels were detected. You can also sort by the label name by specifying
NAME
for the SortBy
input parameter. If there is no NAME
specified,
the default sort is by timestamp.
You can select how results are aggregated by using the AggregateBy
input parameter.
The default aggregation method is TIMESTAMPS
. You can also aggregate by SEGMENTS
,
which aggregates all instances of labels detected in a given segment.
The returned Labels array may include the following attributes:
Name - The name of the detected label.
Confidence - The level of confidence in the label assigned to a detected object.
Parents - The ancestor labels for a detected label. GetLabelDetection returns a hierarchical taxonomy of detected labels. For example, a detected car might be assigned the label car. The label car has two parent labels: Vehicle (its parent) and Transportation (its grandparent). The response includes the all ancestors for a label, where every ancestor is a unique label. In the previous example, Car, Vehicle, and Transportation are returned as unique labels in the response.
Aliases - Possible Aliases for the label.
Categories - The label categories that the detected label belongs to.
BoundingBox — Bounding boxes are described for all instances of detected common object labels, returned in an array of Instance objects. An Instance object contains a BoundingBox object, describing the location of the label on the input image. It also includes the confidence for the accuracy of the detected bounding box.
Timestamp - Time, in milliseconds from the start of the video, that the label was
detected. For aggregation by SEGMENTS
, the StartTimestampMillis
, EndTimestampMillis
,
and DurationMillis
structures are what define a segment. Although the “Timestamp”
structure is still returned with each label, its value is set to be the same as StartTimestampMillis
.
Timestamp and Bounding box information are returned for detected Instances, only if
aggregation is done by TIMESTAMPS
. If aggregating by SEGMENTS
, information
about detected instances isn’t returned.
The version of the label model used for the detection is also returned.
Note DominantColors
isn't returned for Instances
, although it is
shown as part of the response in the sample seen below.
Use MaxResults
parameter to limit the number of labels returned. If there are
more results than specified in MaxResults
, the value of NextToken
in
the operation response contains a pagination token for getting the next set of results.
To get the next page of results, call GetlabelDetection
and populate the NextToken
request parameter with the token value returned from the previous call to GetLabelDetection
.
If you are retrieving results while using the Amazon Simple Notification Service, note that you will receive an "ERROR" notification if the job encounters an issue.
This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginGetLabelDetection and EndGetLabelDetection.
Namespace: Amazon.Rekognition
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z
public virtual Task<GetLabelDetectionResponse> GetLabelDetectionAsync( GetLabelDetectionRequest request, CancellationToken cancellationToken )
Container for the necessary parameters to execute the GetLabelDetection service method.
A cancellation token that can be used by other objects or threads to receive notice of cancellation.
Exception | Condition |
---|---|
AccessDeniedException | You are not authorized to perform the action. |
InternalServerErrorException | Amazon Rekognition experienced a service issue. Try your call again. |
InvalidPaginationTokenException | Pagination token in the request is not valid. |
InvalidParameterException | Input parameter violated a constraint. Validate your parameter before calling the API operation again. |
ProvisionedThroughputExceededException | The number of requests exceeded your throughput limit. If you want to increase this limit, contact Amazon Rekognition. |
ResourceNotFoundException | The resource specified in the request cannot be found. |
ThrottlingException | Amazon Rekognition is temporarily unable to process the request. Try your call again. |
.NET:
Supported in: 8.0 and newer, Core 3.1
.NET Standard:
Supported in: 2.0
.NET Framework:
Supported in: 4.5 and newer