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Container for the parameters to the SearchFacesByImage operation.
For a given input image, first detects the largest face in the image, and then searches
the specified collection for matching faces. The operation compares the features of
the input face with faces in the specified collection.
To search for all faces in an input image, you might first call the IndexFaces
operation, and then use the face IDs returned in subsequent calls to the SearchFaces
operation.
You can also call the DetectFaces
operation and use the bounding boxes in
the response to make face crops, which then you can pass in to the SearchFacesByImage
operation.
You pass the input image either as base64-encoded image bytes or as a reference to an image in an Amazon S3 bucket. If you use the AWS CLI to call Amazon Rekognition operations, passing image bytes is not supported. The image must be either a PNG or JPEG formatted file.
The response returns an array of faces that match, ordered by similarity score with
the highest similarity first. More specifically, it is an array of metadata for each
face match found. Along with the metadata, the response also includes a similarity
indicating how similar the face is to the input face. In the response, the operation
also returns the bounding box (and a confidence level that the bounding box contains
a face) of the face that Amazon Rekognition used for the input image.
If no faces are detected in the input image, SearchFacesByImage
returns an
InvalidParameterException
error.
For an example, Searching for a Face Using an Image in the Amazon Rekognition Developer Guide.
The QualityFilter
input parameter allows you to filter out detected faces that
don’t meet a required quality bar. The quality bar is based on a variety of common
use cases. Use QualityFilter
to set the quality bar for filtering by specifying
LOW
, MEDIUM
, or HIGH
. If you do not want to filter detected faces,
specify NONE
. The default value is NONE
.
To use quality filtering, you need a collection associated with version 3 of the face model or higher. To get the version of the face model associated with a collection, call DescribeCollection.
This operation requires permissions to perform the rekognition:SearchFacesByImage
action.
Namespace: Amazon.Rekognition.Model
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z
public class SearchFacesByImageRequest : AmazonRekognitionRequest IAmazonWebServiceRequest
The SearchFacesByImageRequest type exposes the following members
Name | Description | |
---|---|---|
SearchFacesByImageRequest() |
Name | Type | Description | |
---|---|---|---|
CollectionId | System.String |
Gets and sets the property CollectionId. ID of the collection to search. |
|
FaceMatchThreshold | System.Single |
Gets and sets the property FaceMatchThreshold. (Optional) Specifies the minimum confidence in the face match to return. For example, don't return any matches where confidence in matches is less than 70%. The default value is 80%. |
|
Image | Amazon.Rekognition.Model.Image |
Gets and sets the property Image. The input image as base64-encoded bytes or an S3 object. If you use the AWS CLI to call Amazon Rekognition operations, passing base64-encoded image bytes is not supported.
If you are using an AWS SDK to call Amazon Rekognition, you might not need to base64-encode
image bytes passed using the |
|
MaxFaces | System.Int32 |
Gets and sets the property MaxFaces. Maximum number of faces to return. The operation returns the maximum number of faces with the highest confidence in the match. |
|
QualityFilter | Amazon.Rekognition.QualityFilter |
Gets and sets the property QualityFilter.
A filter that specifies a quality bar for how much filtering is done to identify faces.
Filtered faces aren't searched for in the collection. If you specify To use quality filtering, the collection you are using must be associated with version 3 of the face model or higher. |
This operation searches for faces in a Rekognition collection that match the largest face in an S3 bucket stored image.
var client = new AmazonRekognitionClient(); var response = client.SearchFacesByImage(new SearchFacesByImageRequest { CollectionId = "myphotos", FaceMatchThreshold = 95, Image = new Image { S3Object = new S3Object { Bucket = "mybucket", Name = "myphoto" } }, MaxFaces = 5 }); List<FaceMatch> faceMatches = response.FaceMatches; BoundingBox searchedFaceBoundingBox = response.SearchedFaceBoundingBox; float searchedFaceConfidence = response.SearchedFaceConfidence;
.NET:
Supported in: 8.0 and newer, Core 3.1
.NET Standard:
Supported in: 2.0
.NET Framework:
Supported in: 4.5 and newer, 3.5