Listing faces and associated users
in a collection
You can use the ListFaces operation
to list faces and their associated users in a collection.
For more information, see Managing faces in a collection.
To list faces in a collection (SDK)
-
If you haven't already:
-
Create or update a user with AmazonRekognitionFullAccess
permissions. For more information, see Step 1: Set up an AWS account and create a
User.
-
Install and configure the AWS CLI and the AWS SDKs. For more
information, see Step 2: Set up the AWS CLI and AWS SDKs.
-
Use the following examples to call the ListFaces
operation.
- Java
-
This example displays a list of faces in a collection.
Change the value of collectionId to the desired
collection.
//Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-developer-guide/blob/master/LICENSE-SAMPLECODE.)
package aws.example.rekognition.image;
import com.amazonaws.services.rekognition.AmazonRekognition;
import com.amazonaws.services.rekognition.AmazonRekognitionClientBuilder;
import com.amazonaws.services.rekognition.model.Face;
import com.amazonaws.services.rekognition.model.ListFacesRequest;
import com.amazonaws.services.rekognition.model.ListFacesResult;
import java.util.List;
import com.fasterxml.jackson.databind.ObjectMapper;
public class ListFacesInCollection {
public static final String collectionId = "MyCollection";
public static void main(String[] args) throws Exception {
AmazonRekognition rekognitionClient = AmazonRekognitionClientBuilder.defaultClient();
ObjectMapper objectMapper = new ObjectMapper();
ListFacesResult listFacesResult = null;
System.out.println("Faces in collection " + collectionId);
String paginationToken = null;
do {
if (listFacesResult != null) {
paginationToken = listFacesResult.getNextToken();
}
ListFacesRequest listFacesRequest = new ListFacesRequest()
.withCollectionId(collectionId)
.withMaxResults(1)
.withNextToken(paginationToken);
listFacesResult = rekognitionClient.listFaces(listFacesRequest);
List < Face > faces = listFacesResult.getFaces();
for (Face face: faces) {
System.out.println(objectMapper.writerWithDefaultPrettyPrinter()
.writeValueAsString(face));
}
} while (listFacesResult != null && listFacesResult.getNextToken() !=
null);
}
}
- Java V2
-
This code is taken from the AWS Documentation SDK examples
GitHub repository. See the full example here.
// snippet-start:[rekognition.java2.list_faces_collection.import]
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.rekognition.RekognitionClient;
import software.amazon.awssdk.services.rekognition.model.Face;
import software.amazon.awssdk.services.rekognition.model.ListFacesRequest;
import software.amazon.awssdk.services.rekognition.model.ListFacesResponse;
import software.amazon.awssdk.services.rekognition.model.RekognitionException;
import java.util.List;
// snippet-end:[rekognition.java2.list_faces_collection.import]
/**
* Before running this Java V2 code example, set up your development environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class ListFacesInCollection {
public static void main(String[] args) {
final String usage = "\n" +
"Usage: " +
" <collectionId>\n\n" +
"Where:\n" +
" collectionId - The name of the collection. \n\n";
if (args.length < 1) {
System.out.println(usage);
System.exit(1);
}
String collectionId = args[0];
Region region = Region.US_EAST_1;
RekognitionClient rekClient = RekognitionClient.builder()
.region(region)
.credentialsProvider(ProfileCredentialsProvider.create("profile-name"))
.build();
System.out.println("Faces in collection " + collectionId);
listFacesCollection(rekClient, collectionId) ;
rekClient.close();
}
// snippet-start:[rekognition.java2.list_faces_collection.main]
public static void listFacesCollection(RekognitionClient rekClient, String collectionId ) {
try {
ListFacesRequest facesRequest = ListFacesRequest.builder()
.collectionId(collectionId)
.maxResults(10)
.build();
ListFacesResponse facesResponse = rekClient.listFaces(facesRequest);
List<Face> faces = facesResponse.faces();
for (Face face: faces) {
System.out.println("Confidence level there is a face: "+face.confidence());
System.out.println("The face Id value is "+face.faceId());
}
} catch (RekognitionException e) {
System.out.println(e.getMessage());
System.exit(1);
}
}
// snippet-end:[rekognition.java2.list_faces_collection.main]
}
- AWS CLI
-
This AWS CLI command displays the JSON output for the
list-faces CLI operation. Replace the value of
collection-id with the name of the collection you
want to list. Replace the value of profile_name in the
line that creates the Rekognition session with the name of your developer
profile.
aws rekognition list-faces --collection-id "collection-id" --profile profile-name
- Python
-
This example displays a list of faces in a collection.
Replace the value of profile_name in the line that
creates the Rekognition session with the name of your developer profile.
# Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
# PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-developer-guide/blob/master/LICENSE-SAMPLECODE.)
import boto3
def list_faces_in_collection(collection_id):
maxResults = 2
faces_count = 0
tokens = True
session = boto3.Session(profile_name='profile-name')
client = session.client('rekognition')
response = client.list_faces(CollectionId=collection_id,
MaxResults=maxResults)
print('Faces in collection ' + collection_id)
while tokens:
faces = response['Faces']
for face in faces:
print(face)
faces_count += 1
if 'NextToken' in response:
nextToken = response['NextToken']
response = client.list_faces(CollectionId=collection_id,
NextToken=nextToken, MaxResults=maxResults)
else:
tokens = False
return faces_count
def main():
collection_id = 'collection-id'
faces_count = list_faces_in_collection(collection_id)
print("faces count: " + str(faces_count))
if __name__ == "__main__":
main()
- .NET
-
This example displays a list of faces in a collection.
Change the value of collectionId to the desired
collection.
//Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
//PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-developer-guide/blob/master/LICENSE-SAMPLECODE.)
using System;
using Amazon.Rekognition;
using Amazon.Rekognition.Model;
public class ListFaces
{
public static void Example()
{
String collectionId = "MyCollection";
AmazonRekognitionClient rekognitionClient = new AmazonRekognitionClient();
ListFacesResponse listFacesResponse = null;
Console.WriteLine("Faces in collection " + collectionId);
String paginationToken = null;
do
{
if (listFacesResponse != null)
paginationToken = listFacesResponse.NextToken;
ListFacesRequest listFacesRequest = new ListFacesRequest()
{
CollectionId = collectionId,
MaxResults = 1,
NextToken = paginationToken
};
listFacesResponse = rekognitionClient.ListFaces(listFacesRequest);
foreach(Face face in listFacesResponse.Faces)
Console.WriteLine(face.FaceId);
} while (listFacesResponse != null && !String.IsNullOrEmpty(listFacesResponse.NextToken));
}
}
ListFaces operation request
The input to ListFaces is the ID of the collection that you want to
list faces for. MaxResults is the maximum number of faces to return.
ListFaces also takes in a list of face IDs to filter the results with, and a user ID
provided to list only faces associated with the given user.
{
"CollectionId": "MyCollection",
"MaxResults": 1
}
If the response has more faces than are requested by MaxResults, a
token is returned that you can use to get the next set of results, in a subsequent
call to ListFaces. For example:
{
"CollectionId": "MyCollection",
"NextToken": "sm+5ythT3aeEVIR4WA....",
"MaxResults": 1
}
ListFaces operation response
The response from ListFaces is information about the face metadata
that's stored in the specified collection.
-
FaceModelVersion – The version of
the face model that's associated with the collection. For more information,
see Understanding model versioning.
-
Faces – Information about the faces
in the collection. This includes information about BoundingBox, confidence, image identifiers, and the face ID.
For more information, see Face.
-
NextToken – The token that's used to
get the next set of results.
{
"FaceModelVersion": "6.0",
"Faces": [
{
"Confidence": 99.76940155029297,
"IndexFacesModelVersion": "6.0",
"UserId": "demoUser2",
"ImageId": "56a0ca74-1c83-39dd-b363-051a64168a65",
"BoundingBox": {
"Width": 0.03177810087800026,
"Top": 0.36568498611450195,
"Left": 0.3453829884529114,
"Height": 0.056759100407361984
},
"FaceId": "c92265d4-5f9c-43af-a58e-12be0ce02bc3"
},
{
"BoundingBox": {
"Width": 0.03254450112581253,
"Top": 0.6080359816551208,
"Left": 0.5160620212554932,
"Height": 0.06347999721765518
},
"IndexFacesModelVersion": "6.0",
"FaceId": "851cb847-dccc-4fea-9309-9f4805967855",
"Confidence": 99.94369506835938,
"ImageId": "a8aed589-ceec-35f7-9c04-82e0b546b024"
},
{
"BoundingBox": {
"Width": 0.03094629943370819,
"Top": 0.4218429923057556,
"Left": 0.6513839960098267,
"Height": 0.05266290158033371
},
"IndexFacesModelVersion": "6.0",
"FaceId": "c0eb3b65-24a0-41e1-b23a-1908b1aaeac1",
"Confidence": 99.82969665527344,
"ImageId": "56a0ca74-1c83-39dd-b363-051a64168a65"
}
]
}
