Use SearchFaces with an AWS SDK or CLI

    using System;
    using System.Threading.Tasks;
    using Amazon.Rekognition;
    using Amazon.Rekognition.Model;

    /// <summary>
    /// Uses the Amazon Rekognition Service to find faces in an image that
    /// match the face Id provided in the method request.
    /// </summary>
    public class SearchFacesMatchingId
    {
        public static async Task Main()
        {
            string collectionId = "MyCollection";
            string faceId = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";

            var rekognitionClient = new AmazonRekognitionClient();

            // Search collection for faces matching the face id.
            var searchFacesRequest = new SearchFacesRequest
            {
                CollectionId = collectionId,
                FaceId = faceId,
                FaceMatchThreshold = 70F,
                MaxFaces = 2,
            };

            SearchFacesResponse searchFacesResponse = await rekognitionClient.SearchFacesAsync(searchFacesRequest);

            Console.WriteLine("Face matching faceId " + faceId);

            Console.WriteLine("Matche(s): ");
            searchFacesResponse.FaceMatches.ForEach(face =>
            {
                Console.WriteLine($"FaceId: {face.Face.FaceId} Similarity: {face.Similarity}");
            });
        }
    }

To search for faces in a collection that match a face ID.

The following search-faces command searches for faces in a collection that match the specified face ID.

aws rekognition search-faces \
    --face-id 8d3cfc70-4ba8-4b36-9644-90fba29c2dac \
    --collection-id MyCollection

Output:

{
    "SearchedFaceId": "8d3cfc70-4ba8-4b36-9644-90fba29c2dac",
    "FaceModelVersion": "3.0",
    "FaceMatches": [
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.48166701197624207,
                    "Top": 0.20999999344348907,
                    "Left": 0.21250000596046448,
                    "Height": 0.36125001311302185
                },
                "FaceId": "bd4ceb4d-9acc-4ab7-8ef8-1c2d2ba0a66a",
                "ExternalImageId": "image1.jpg",
                "Confidence": 99.99949645996094,
                "ImageId": "5e1a7588-e5a0-5ee3-bd00-c642518dfe3a"
            },
            "Similarity": 99.30997467041016
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.18562500178813934,
                    "Top": 0.1618019938468933,
                    "Left": 0.5575000047683716,
                    "Height": 0.24770599603652954
                },
                "FaceId": "ce7ed422-2132-4a11-ab14-06c5c410f29f",
                "ExternalImageId": "example-image.jpg",
                "Confidence": 99.99340057373047,
                "ImageId": "8d67061e-90d2-598f-9fbd-29c8497039c0"
            },
            "Similarity": 99.24862670898438
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.18562500178813934,
                    "Top": 0.1618019938468933,
                    "Left": 0.5575000047683716,
                    "Height": 0.24770599603652954
                },
                "FaceId": "13692fe4-990a-4679-b14a-5ac23d135eab",
                "ExternalImageId": "image3.jpg",
                "Confidence": 99.99340057373047,
                "ImageId": "8df18239-9ad1-5acd-a46a-6581ff98f51b"
            },
            "Similarity": 99.24862670898438
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.5349419713020325,
                    "Top": 0.29124999046325684,
                    "Left": 0.16389399766921997,
                    "Height": 0.40187498927116394
                },
                "FaceId": "745f7509-b1fa-44e0-8b95-367b1359638a",
                "ExternalImageId": "image9.jpg",
                "Confidence": 99.99979400634766,
                "ImageId": "67a34327-48d1-5179-b042-01e52ccfeada"
            },
            "Similarity": 96.73158264160156
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.5307819843292236,
                    "Top": 0.2862499952316284,
                    "Left": 0.1564060002565384,
                    "Height": 0.3987500071525574
                },
                "FaceId": "2eb5f3fd-e2a9-4b1c-a89f-afa0a518fe06",
                "ExternalImageId": "image10.jpg",
                "Confidence": 99.99970245361328,
                "ImageId": "3c314792-197d-528d-bbb6-798ed012c150"
            },
            "Similarity": 96.48291015625
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.5074880123138428,
                    "Top": 0.3774999976158142,
                    "Left": 0.18302799761295319,
                    "Height": 0.3812499940395355
                },
                "FaceId": "086261e8-6deb-4bc0-ac73-ab22323cc38d",
                "ExternalImageId": "image6.jpg",
                "Confidence": 99.99930572509766,
                "ImageId": "ae1593b0-a8f6-5e24-a306-abf529e276fa"
            },
            "Similarity": 96.43287658691406
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.5574039816856384,
                    "Top": 0.37187498807907104,
                    "Left": 0.14559100568294525,
                    "Height": 0.4181250035762787
                },
                "FaceId": "11c4bd3c-19c5-4eb8-aecc-24feb93a26e1",
                "ExternalImageId": "image5.jpg",
                "Confidence": 99.99960327148438,
                "ImageId": "80739b4d-883f-5b78-97cf-5124038e26b9"
            },
            "Similarity": 95.25305938720703
        },
        {
            "Face": {
                "BoundingBox": {
                    "Width": 0.5773710012435913,
                    "Top": 0.34437501430511475,
                    "Left": 0.12396000325679779,
                    "Height": 0.4337500035762787
                },
                "FaceId": "57189455-42b0-4839-a86c-abda48b13174",
                "ExternalImageId": "image8.jpg",
                "Confidence": 100.0,
                "ImageId": "0aff2f37-e7a2-5dbc-a3a3-4ef6ec18eaa0"
            },
            "Similarity": 95.22837829589844
        }
    ]
}

For more information, see Searching for a Face Using Its Face ID in the Amazon Rekognition Developer Guide.

import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.rekognition.RekognitionClient;
import software.amazon.awssdk.services.rekognition.model.RekognitionException;
import software.amazon.awssdk.services.rekognition.model.SearchFacesByImageRequest;
import software.amazon.awssdk.services.rekognition.model.Image;
import software.amazon.awssdk.services.rekognition.model.SearchFacesByImageResponse;
import software.amazon.awssdk.services.rekognition.model.FaceMatch;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.List;

/**
 * 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 SearchFaceMatchingImageCollection {
    public static void main(String[] args) {
        final String usage = """

                Usage:    <collectionId> <sourceImage>

                Where:
                   collectionId - The id of the collection. \s
                   sourceImage - The path to the image (for example, C:\\AWS\\pic1.png).\s

                """;

        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        String collectionId = args[0];
        String sourceImage = args[1];
        Region region = Region.US_EAST_1;
        RekognitionClient rekClient = RekognitionClient.builder()
                .region(region)
                .build();

        System.out.println("Searching for a face in a collections");
        searchFaceInCollection(rekClient, collectionId, sourceImage);
        rekClient.close();
    }

    public static void searchFaceInCollection(RekognitionClient rekClient, String collectionId, String sourceImage) {
        try {
            InputStream sourceStream = new FileInputStream(new File(sourceImage));
            SdkBytes sourceBytes = SdkBytes.fromInputStream(sourceStream);
            Image souImage = Image.builder()
                    .bytes(sourceBytes)
                    .build();

            SearchFacesByImageRequest facesByImageRequest = SearchFacesByImageRequest.builder()
                    .image(souImage)
                    .maxFaces(10)
                    .faceMatchThreshold(70F)
                    .collectionId(collectionId)
                    .build();

            SearchFacesByImageResponse imageResponse = rekClient.searchFacesByImage(facesByImageRequest);
            System.out.println("Faces matching in the collection");
            List<FaceMatch> faceImageMatches = imageResponse.faceMatches();
            for (FaceMatch face : faceImageMatches) {
                System.out.println("The similarity level is  " + face.similarity());
                System.out.println();
            }

        } catch (RekognitionException | FileNotFoundException e) {
            System.out.println(e.getMessage());
            System.exit(1);
        }
    }
}

class RekognitionCollection:
    """
    Encapsulates an Amazon Rekognition collection. This class is a thin wrapper
    around parts of the Boto3 Amazon Rekognition API.
    """

    def __init__(self, collection, rekognition_client):
        """
        Initializes a collection object.

        :param collection: Collection data in the format returned by a call to
                           create_collection.
        :param rekognition_client: A Boto3 Rekognition client.
        """
        self.collection_id = collection["CollectionId"]
        self.collection_arn, self.face_count, self.created = self._unpack_collection(
            collection
        )
        self.rekognition_client = rekognition_client

    @staticmethod
    def _unpack_collection(collection):
        """
        Unpacks optional parts of a collection that can be returned by
        describe_collection.

        :param collection: The collection data.
        :return: A tuple of the data in the collection.
        """
        return (
            collection.get("CollectionArn"),
            collection.get("FaceCount", 0),
            collection.get("CreationTimestamp"),
        )


    def search_faces(self, face_id, threshold, max_faces):
        """
        Searches for faces in the collection that match another face from the
        collection.

        :param face_id: The ID of the face in the collection to search for.
        :param threshold: The match confidence must be greater than this value
                          for a face to be included in the results.
        :param max_faces: The maximum number of faces to return.
        :return: The list of matching faces found in the collection. This list does
                 not contain the face specified by `face_id`.
        """
        try:
            response = self.rekognition_client.search_faces(
                CollectionId=self.collection_id,
                FaceId=face_id,
                FaceMatchThreshold=threshold,
                MaxFaces=max_faces,
            )
            faces = [RekognitionFace(face["Face"]) for face in response["FaceMatches"]]
            logger.info(
                "Found %s faces in %s that match %s.",
                len(faces),
                self.collection_id,
                face_id,
            )
        except ClientError:
            logger.exception(
                "Couldn't search for faces in %s that match %s.",
                self.collection_id,
                face_id,
            )
            raise
        else:
            return faces