Add option to switch FaceAPI prediction mode

CatalystCode · Aug 14, 2018 · 36fb41b · 36fb41b
1 parent 1b97335
commit 36fb41b
Show file tree

Hide file tree

Showing 2 changed files with 61 additions and 11 deletions.
diff --git a/algorithms/FaceApi/Cli.cs b/algorithms/FaceApi/Cli.cs
@@ -15,13 +15,13 @@ static void Main(string[] args)
         static async Task MainAsync(string[] args)
         {
             var settings = new Settings(args);
-            if (!settings.TryParse(out string apiKey, out string apiEndpoint, out double matchThreshold))
+            if (!settings.TryParse(out string apiKey, out string apiEndpoint, out double matchThreshold, out PredictionMode predictionMode))
             {
                 await Console.Error.WriteLineAsync("Missing api-key and api-endpoint settings");
                 return;
             }
 
-            var faceIdentifier = new FaceIdentifier(apiKey, apiEndpoint);
+            var faceIdentifier = new FaceIdentifier(apiKey, apiEndpoint, predictionMode);
 
             if (settings.TryParseForTraining(out string trainSetRoot))
             {
@@ -63,26 +63,31 @@ static async Task MainAsync(string[] args)
 
     class Settings
     {
+        private static readonly PredictionMode DefaultPredictionMode = PredictionMode.Identify;
+        private static readonly double DefaultMatchThreshold = 0.6;
+
         private string[] Args { get; }
 
         public Settings(string[] args)
         {
             Args = args;
         }
 
-        public bool TryParse(out string apiKey, out string apiEndpoint, out double matchThreshold)
+        public bool TryParse(out string apiKey, out string apiEndpoint, out double matchThreshold, out PredictionMode predictionMode)
         {
             if (ApiKey == null || ApiEndpoint == null)
             {
                 apiKey = null;
                 apiEndpoint = null;
-                matchThreshold = -1;
+                matchThreshold = DefaultMatchThreshold;
+                predictionMode = DefaultPredictionMode;
                 return false;
             }
 
             apiKey = ApiKey;
             apiEndpoint = ApiEndpoint;
             matchThreshold = MatchThreshold;
+            predictionMode = PredictionMode;
             return true;
         }
 
@@ -164,18 +169,32 @@ private double MatchThreshold
         {
             get
             {
-                const double defaultMatchThreshold = 0.6;
                 var matchThreshold = Environment.GetEnvironmentVariable("FACE_API_MATCH_THRESHOLD");
 
                 if (matchThreshold == null || !double.TryParse(matchThreshold, out double parsedMatchThreshold))
                 {
-                    return defaultMatchThreshold;
+                    return DefaultMatchThreshold;
                 }
 
                 return parsedMatchThreshold;
             }
         }
 
+        private PredictionMode PredictionMode
+        {
+            get
+            {
+                var predictionMode = Environment.GetEnvironmentVariable("FACE_API_PREDICTION_MODE");
+
+                if (predictionMode == null || !Enum.TryParse(typeof(PredictionMode), predictionMode, out object parsedPredictionMode))
+                {
+                    return DefaultPredictionMode;
+                }
+
+                return (PredictionMode)parsedPredictionMode;
+            }
+        }
+
         private string GroupId
         {
             get => Environment.GetEnvironmentVariable("FACE_API_GROUP_ID");

diff --git a/algorithms/FaceApi/FaceIdentifier.cs b/algorithms/FaceApi/FaceIdentifier.cs
@@ -17,15 +17,18 @@ public class FaceIdentifier
 
         private TimeLimiter RateLimit { get; }
         private FaceClient Client { get; }
+        private PredictionMode PredictionMode { get; }
 
-        public FaceIdentifier(string apiKey, string apiEndpoint)
+        public FaceIdentifier(string apiKey, string apiEndpoint, PredictionMode predictionMode)
         {
             Client = new FaceClient(new ApiKeyServiceClientCredentials(apiKey))
             {
                 Endpoint = apiEndpoint
             };
 
             RateLimit = TimeLimiter.GetFromMaxCountByInterval(RateLimitRequests, RateLimitInterval);
+
+            PredictionMode = predictionMode;
         }
 
         public async Task<bool> Predict(string groupId, double matchThreshold, string imagePath1, string imagePath2)
@@ -39,11 +42,17 @@ public async Task<bool> Predict(string groupId, double matchThreshold, string im
                 return false;
             }
 
-            var allPeople = await IdentifyPeople(faces1.Concat(faces2), groupId, matchThreshold);
-            var people1 = allPeople.Where(candidates => faces1.Contains(candidates.FaceId)).SelectMany(candidates => candidates.Candidates).Select(person => person.PersonId).ToHashSet();
-            var people2 = allPeople.Where(candidates => faces2.Contains(candidates.FaceId)).SelectMany(candidates => candidates.Candidates).Select(person => person.PersonId).ToHashSet();
+            switch (PredictionMode)
+            {
+                case PredictionMode.Identify:
+                    return await PredictWithIdentify(groupId, matchThreshold, faces1, faces2);
 
-            return people1.Any(person => people2.Contains(person));
+                case PredictionMode.Verify:
+                    return await PredictWithVerify(matchThreshold, faces1, faces2);
+
+                default:
+                    throw new NotImplementedException($"{PredictionMode}");
+            }
         }
 
         public async Task<string> Train(string trainSetRoot)
@@ -171,5 +180,27 @@ private async Task<PersistedFace> AddFace(string groupId, Guid personId, string
                 });
             }
         }
+
+        private async Task<bool> PredictWithIdentify(string groupId, double matchThreshold, IList<Guid> faces1, IList<Guid> faces2)
+        {
+            var allPeople = await IdentifyPeople(faces1.Concat(faces2), groupId, matchThreshold);
+            var people1 = allPeople.Where(candidates => faces1.Contains(candidates.FaceId)).SelectMany(candidates => candidates.Candidates).Select(person => person.PersonId).ToHashSet();
+            var people2 = allPeople.Where(candidates => faces2.Contains(candidates.FaceId)).SelectMany(candidates => candidates.Candidates).Select(person => person.PersonId).ToHashSet();
+
+            return people1.Any(person => people2.Contains(person));
+        }
+
+        private async Task<bool> PredictWithVerify(double matchThreshold, IList<Guid> faces1, IList<Guid> faces2)
+        {
+            var verifications = await Task.WhenAll(faces1.SelectMany(face1 => faces2.Select(face2 => Client.Face.VerifyFaceToFaceAsync(face1, face2))));
+
+            return verifications.Any(result => result.Confidence >= matchThreshold);
+        }
+    }
+
+    public enum PredictionMode
+    {
+        Identify,
+        Verify
     }
 }