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Container for the parameters to the IndexFaces operation. Detects faces in the input image and adds them to the specified collection.
Amazon Rekognition doesn't save the actual faces that are detected. Instead, the underlying detection algorithm first detects the faces in the input image. For each face, the algorithm extracts facial features into a feature vector, and stores it in the backend database. Amazon Rekognition uses feature vectors when it performs face match and search operations using the SearchFaces and SearchFacesByImage operations.
For more information, see Adding faces to a collection in the Amazon Rekognition Developer Guide.
To get the number of faces in a collection, call DescribeCollection.
If you're using version 1.0 of the face detection model, IndexFaces
indexes
the 15 largest faces in the input image. Later versions of the face detection model
index the 100 largest faces in the input image.
If you're using version 4 or later of the face model, image orientation information
is not returned in the OrientationCorrection
field.
To determine which version of the model you're using, call DescribeCollection
and supply the collection ID. You can also get the model version from the value of
FaceModelVersion
in the response from IndexFaces
For more information, see Model Versioning in the Amazon Rekognition Developer Guide.
If you provide the optional ExternalImageId
for the input image you provided,
Amazon Rekognition associates this ID with all faces that it detects. When you call
the ListFaces operation, the response returns the external ID. You can use
this external image ID to create a client-side index to associate the faces with each
image. You can then use the index to find all faces in an image.
You can specify the maximum number of faces to index with the MaxFaces
input
parameter. This is useful when you want to index the largest faces in an image and
don't want to index smaller faces, such as those belonging to people standing in the
background.
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. By default, IndexFaces
chooses the quality bar that's used to filter
faces. You can also explicitly choose the quality bar. Use QualityFilter
, to
set the quality bar by specifying LOW
, MEDIUM
, or HIGH
. If you
do not want to filter detected faces, specify 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.
Information about faces detected in an image, but not indexed, is returned in an array
of UnindexedFace objects, UnindexedFaces
. Faces aren't indexed for reasons
such as:
The number of faces detected exceeds the value of the MaxFaces
request parameter.
The face is too small compared to the image dimensions.
The face is too blurry.
The image is too dark.
The face has an extreme pose.
The face doesn’t have enough detail to be suitable for face search.
In response, the IndexFaces
operation returns an array of metadata for all
detected faces, FaceRecords
. This includes:
The bounding box, BoundingBox
, of the detected face.
A confidence value, Confidence
, which indicates the confidence that the bounding
box contains a face.
A face ID, FaceId
, assigned by the service for each face that's detected and
stored.
An image ID, ImageId
, assigned by the service for the input image.
If you request ALL
or specific facial attributes (e.g., FACE_OCCLUDED
)
by using the detectionAttributes parameter, Amazon Rekognition returns detailed facial
attributes, such as facial landmarks (for example, location of eye and mouth), facial
occlusion, and other facial attributes.
If you provide the same image, specify the same collection, and use the same external
ID in the IndexFaces
operation, Amazon Rekognition doesn't save duplicate face
metadata.
The input image is passed 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 isn't supported. The image must be formatted as a PNG or JPEG file.
This operation requires permissions to perform the rekognition:IndexFaces
action.
Namespace: Amazon.Rekognition.Model
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z
public class IndexFacesRequest : AmazonRekognitionRequest IAmazonWebServiceRequest
The IndexFacesRequest type exposes the following members
Name | Description | |
---|---|---|
IndexFacesRequest() |
Name | Type | Description | |
---|---|---|---|
CollectionId | System.String |
Gets and sets the property CollectionId. The ID of an existing collection to which you want to add the faces that are detected in the input images. |
|
DetectionAttributes | System.Collections.Generic.List<System.String> |
Gets and sets the property DetectionAttributes.
An array of facial attributes you want to be returned. A
If you provide both, |
|
ExternalImageId | System.String |
Gets and sets the property ExternalImageId. The ID you want to assign to all the faces detected in the image. |
|
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 isn't 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.
The maximum number of faces to index. The value of
If
The faces that are returned by
|
|
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 indexed. 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 detects faces in an image and adds them to the specified Rekognition collection.
var client = new AmazonRekognitionClient(); var response = client.IndexFaces(new IndexFacesRequest { CollectionId = "myphotos", DetectionAttributes = new List<string> { }, ExternalImageId = "myphotoid", Image = new Image { S3Object = new S3Object { Bucket = "mybucket", Name = "myphoto" } } }); List<FaceRecord> faceRecords = response.FaceRecords; string orientationCorrection = response.OrientationCorrection;
.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