getFaceSearch method

Future<GetFaceSearchResponse> getFaceSearch({ required String jobId, int? maxResults, String? nextToken, FaceSearchSortBy? sortBy, })

Gets the face search results for Amazon Rekognition Video face search started by StartFaceSearch. The search returns faces in a collection that match the faces of persons detected in a video. It also includes the time(s) that faces are matched in the video.

Face search in a video is an asynchronous operation. You start face search by calling to StartFaceSearch which returns a job identifier (JobId). When the search operation finishes, Amazon Rekognition Video publishes a completion status to the Amazon Simple Notification Service topic registered in the initial call to StartFaceSearch. To get the search results, first check that the status value published to the Amazon SNS topic is SUCCEEDED. If so, call GetFaceSearch and pass the job identifier (JobId) from the initial call to StartFaceSearch.

For more information, see Searching Faces in a Collection in the Amazon Rekognition Developer Guide.

The search results are retured in an array, Persons, of PersonMatch objects. EachPersonMatch element contains details about the matching faces in the input collection, person information (facial attributes, bounding boxes, and person identifer) for the matched person, and the time the person was matched in the video. By default, the Persons array is sorted by the time, in milliseconds from the start of the video, persons are matched. You can also sort by persons by specifying INDEX for the SORTBY input parameter.

May throw AccessDeniedException. May throw InternalServerError. May throw InvalidParameterException. May throw InvalidPaginationTokenException. May throw ProvisionedThroughputExceededException. May throw ResourceNotFoundException. May throw ThrottlingException.

Parameter jobId : The job identifer for the search request. You get the job identifier from an initial call to StartFaceSearch.

Parameter maxResults : Maximum number of results to return per paginated call. The largest value you can specify is 1000. If you specify a value greater than 1000, a maximum of 1000 results is returned. The default value is 1000.

Parameter nextToken : If the previous response was incomplete (because there is more search results to retrieve), Amazon Rekognition Video returns a pagination token in the response. You can use this pagination token to retrieve the next set of search results.

Parameter sortBy : Sort to use for grouping faces in the response. Use TIMESTAMP to group faces by the time that they are recognized. Use INDEX to sort by recognized faces.

Implementation

Future<GetFaceSearchResponse> getFaceSearch({
  required String jobId,
  int? maxResults,
  String? nextToken,
  FaceSearchSortBy? sortBy,
}) async {
  ArgumentError.checkNotNull(jobId, 'jobId');
  _s.validateStringLength(
    'jobId',
    jobId,
    1,
    64,
    isRequired: true,
  );
  _s.validateNumRange(
    'maxResults',
    maxResults,
    1,
    1152921504606846976,
  );
  _s.validateStringLength(
    'nextToken',
    nextToken,
    0,
    255,
  );
  final headers = <String, String>{
    'Content-Type': 'application/x-amz-json-1.1',
    'X-Amz-Target': 'RekognitionService.GetFaceSearch'
  };
  final jsonResponse = await _protocol.send(
    method: 'POST',
    requestUri: '/',
    exceptionFnMap: _exceptionFns,
    // TODO queryParams
    headers: headers,
    payload: {
      'JobId': jobId,
      if (maxResults != null) 'MaxResults': maxResults,
      if (nextToken != null) 'NextToken': nextToken,
      if (sortBy != null) 'SortBy': sortBy.toValue(),
    },
  );

  return GetFaceSearchResponse.fromJson(jsonResponse.body);
}