Face API - V1.0

Face - Find Similar

Given query face's faceId, to search the similar-looking faces from a faceId array or a faceListId. faceId array contains the faces created by Face - Detect, which will expire in 24 hours after creation. While "faceListId" is created by Face List - Create a Face List containing persistedFaceIds that will not expire. Depending on the input the returned similar faces list contains faceIds or persistedFaceIds ranked by similarity.



Find similar has two working modes, "matchPerson" and "matchFace". "matchPerson" is the default mode that it tries to find faces of the same person as possible by using internal same-person thresholds. It is useful to find a known person's other photos. Note that an empty list will be returned if no faces pass the internal thresholds. "matchFace" mode ignores same-person thresholds and returns ranked similar faces anyway, even the similarity is low. It can be used in the cases like searching celebrity-looking faces.

Http Method

POST

Try it

Request URL

Request headers

(optional)
string
Media type of the body sent to the API.
string
Subscription key which provides access to this API. Found in your Cognitive Services accounts.

Request body

JSON fields in request body:

FieldsTypeDescription
faceIdStringfaceId of the query face. User needs to call Face - Detect first to get a valid faceId. Note that this faceId is not persisted and will expire in 24 hours after the detection call.
faceListIdStringAn existing user-specified unique candidate face list, created in Face List - Create a Face List. Face list contains a set of persistedFaceIds which are persisted and will never expire. Parameter faceListId and faceIds should not be provided at the same time.
faceIdsArrayAn array of candidate faceIds. All of them are created by Face - Detect and the faceIds will expire in 24 hours after the detection call. The number of faceIds is limited to 1000. Parameter faceListId and faceIds should not be provided at the same time.
maxNumOfCandidatesReturned (optional)NumberOptional parameter.
The number of top similar faces returned.
The valid range is [1, 1000].It defaults to 20.
mode (optional)StringOptional parameter.
Similar face searching mode. It can be "matchPerson" or "matchFace". It defaults to "matchPerson".

{    
    "faceId":"c5c24a82-6845-4031-9d5d-978df9175426",
    "faceListId":"sample_list",  
    "maxNumOfCandidatesReturned":10,
    "mode": "matchPerson"
}

Response 200

A successful call returns an array of the most similar faces represented in faceId if the input parameter is faceIds or persistedFaceId if the input parameter is faceListId.

JSON fields in response body:

FieldsTypeDescription
persistedFaceIdStringpersistedFaceId of candidate face when find by faceListId. persistedFaceId in face list is persisted and will not expire. As showed in below response.
faceIdStringfaceId of candidate face when find by faceIds. faceId is created by Face - Detect and will expire in 24 hours after the detection call.
confidenceNumberSimilarity confidence of the candidate face. The higher confidence, the more similar. Range between [0,1].

[
    {
        "persistedFaceId" : "015839fb-fbd9-4f79-ace9-7675fc2f1dd9",    
        "confidence" : 0.82
    },
    ...
]

Response 400

Error code and message returned in JSON:

Error CodeError Message Description
BadArgumentInvalid request body.
BadArgumentmode is invalid.
BadArgumentmaxNumOfCandidatesReturned out of range [1, 1000]
BadArgumentLength of faceIds out of range [1, 1000].
BadArgumentBoth faceListId and faceIds are not provided.
BadArgumentArgument faceListId and faceIds cannot be provided at the same time.
BadArgumentFace list ID is invalid.
FaceNotFoundQuery face cannot be found.
FaceListNotFoundFace list is not found.
FaceListNotReadyFace list is empty.

{    
    "error":{    
        "code":"BadArgument",    
        "message":"Request body is invalid."
    }
}

Response 401

Error code and message returned in JSON:

Error CodeError Message Description
UnspecifiedInvalid subscription Key or user/plan is blocked.

{
    "error":{
        "code": "Unspecified",
        "message": "Access denied due to invalid subscription key. Make sure you are subscribed to an API you are trying to call and provide the right key." 
    }
}

Response 403

{
    "error":{
        "statusCode": 403,
        "message": "Out of call volume quota. Quota will be replenished in 2.12 days." 
    }
}

Response 415

Unsupported media type error. Only "application/json" is valid for this API.

{
    "error":{
        "code":"BadArgument",
        "message":"Invalid Media Type" 
    }
}

Response 429

{
    "error":{
        "statusCode": 429,
        "message": "Rate limit is exceeded. Try again in 26 seconds." 
    }
}

Code samples

@ECHO OFF

curl -v -X POST "https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars"
-H "Content-Type: application/json"
-H "Ocp-Apim-Subscription-Key: {subscription key}"

--data-ascii "{body}" 
using System;
using System.Net.Http.Headers;
using System.Text;
using System.Net.Http;
using System.Web;

namespace CSHttpClientSample
{
    static class Program
    {
        static void Main()
        {
            MakeRequest();
            Console.WriteLine("Hit ENTER to exit...");
            Console.ReadLine();
        }
        
        static async void MakeRequest()
        {
            var client = new HttpClient();
            var queryString = HttpUtility.ParseQueryString(string.Empty);

            // Request headers
            client.DefaultRequestHeaders.Add("Ocp-Apim-Subscription-Key", "{subscription key}");

            var uri = "https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars?" + queryString;

            HttpResponseMessage response;

            // Request body
            byte[] byteData = Encoding.UTF8.GetBytes("{body}");

            using (var content = new ByteArrayContent(byteData))
            {
               content.Headers.ContentType = new MediaTypeHeaderValue("< your content type, i.e. application/json >");
               response = await client.PostAsync(uri, content);
            }

        }
    }
}	
// // This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
import java.net.URI;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class JavaSample 
{
    public static void main(String[] args) 
    {
        HttpClient httpclient = HttpClients.createDefault();

        try
        {
            URIBuilder builder = new URIBuilder("https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars");


            URI uri = builder.build();
            HttpPost request = new HttpPost(uri);
            request.setHeader("Content-Type", "application/json");
            request.setHeader("Ocp-Apim-Subscription-Key", "{subscription key}");


            // Request body
            StringEntity reqEntity = new StringEntity("{body}");
            request.setEntity(reqEntity);

            HttpResponse response = httpclient.execute(request);
            HttpEntity entity = response.getEntity();

            if (entity != null) 
            {
                System.out.println(EntityUtils.toString(entity));
            }
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
}

<!DOCTYPE html>
<html>
<head>
    <title>JSSample</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
</head>
<body>

<script type="text/javascript">
    $(function() {
        var params = {
            // Request parameters
        };
      
        $.ajax({
            url: "https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars?" + $.param(params),
            beforeSend: function(xhrObj){
                // Request headers
                xhrObj.setRequestHeader("Content-Type","application/json");
                xhrObj.setRequestHeader("Ocp-Apim-Subscription-Key","{subscription key}");
            },
            type: "POST",
            // Request body
            data: "{body}",
        })
        .done(function(data) {
            alert("success");
        })
        .fail(function() {
            alert("error");
        });
    });
</script>
</body>
</html>
#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    
    NSString* path = @"https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars";
    NSArray* array = @[
                         // Request parameters
                         @"entities=true",
                      ];
    
    NSString* string = [array componentsJoinedByString:@"&"];
    path = [path stringByAppendingFormat:@"?%@", string];

    NSLog(@"%@", path);

    NSMutableURLRequest* _request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:path]];
    [_request setHTTPMethod:@"POST"];
    // Request headers
    [_request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [_request setValue:@"{subscription key}" forHTTPHeaderField:@"Ocp-Apim-Subscription-Key"];
    // Request body
    [_request setHTTPBody:[@"{body}" dataUsingEncoding:NSUTF8StringEncoding]];
    
    NSURLResponse *response = nil;
    NSError *error = nil;
    NSData* _connectionData = [NSURLConnection sendSynchronousRequest:_request returningResponse:&response error:&error];

    if (nil != error)
    {
        NSLog(@"Error: %@", error);
    }
    else
    {
        NSError* error = nil;
        NSMutableDictionary* json = nil;
        NSString* dataString = [[NSString alloc] initWithData:_connectionData encoding:NSUTF8StringEncoding];
        NSLog(@"%@", dataString);
        
        if (nil != _connectionData)
        {
            json = [NSJSONSerialization JSONObjectWithData:_connectionData options:NSJSONReadingMutableContainers error:&error];
        }
        
        if (error || !json)
        {
            NSLog(@"Could not parse loaded json with error:%@", error);
        }
        
        NSLog(@"%@", json);
        _connectionData = nil;
    }
    
    [pool drain];

    return 0;
}
<?php
// This sample uses the Apache HTTP client from HTTP Components (http://hc.apache.org/httpcomponents-client-ga/)
require_once 'HTTP/Request2.php';

$request = new Http_Request2('https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars');
$url = $request->getUrl();

$headers = array(
    // Request headers
    'Content-Type' => 'application/json',
    'Ocp-Apim-Subscription-Key' => '{subscription key}',
);

$request->setHeader($headers);

$parameters = array(
    // Request parameters
);

$url->setQueryVariables($parameters);

$request->setMethod(HTTP_Request2::METHOD_POST);

// Request body
$request->setBody("{body}");

try
{
    $response = $request->send();
    echo $response->getBody();
}
catch (HttpException $ex)
{
    echo $ex;
}

?>
########### Python 2.7 #############
import httplib, urllib, base64

headers = {
    # Request headers
    'Content-Type': 'application/json',
    'Ocp-Apim-Subscription-Key': '{subscription key}',
}

params = urllib.urlencode({
})

try:
    conn = httplib.HTTPSConnection('westus.api.cognitive.microsoft.com')
    conn.request("POST", "/face/v1.0/findsimilars?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################

########### Python 3.2 #############
import http.client, urllib.request, urllib.parse, urllib.error, base64

headers = {
    # Request headers
    'Content-Type': 'application/json',
    'Ocp-Apim-Subscription-Key': '{subscription key}',
}

params = urllib.parse.urlencode({
})

try:
    conn = http.client.HTTPSConnection('westus.api.cognitive.microsoft.com')
    conn.request("POST", "/face/v1.0/findsimilars?%s" % params, "{body}", headers)
    response = conn.getresponse()
    data = response.read()
    print(data)
    conn.close()
except Exception as e:
    print("[Errno {0}] {1}".format(e.errno, e.strerror))

####################################
require 'net/http'

uri = URI('https://westus.api.cognitive.microsoft.com/face/v1.0/findsimilars')
uri.query = URI.encode_www_form({
})

request = Net::HTTP::Post.new(uri.request_uri)
# Request headers
request['Content-Type'] = 'application/json'
# Request headers
request['Ocp-Apim-Subscription-Key'] = '{subscription key}'
# Request body
request.body = "{body}"

response = Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https') do |http|
    http.request(request)
end

puts response.body