private static async Task <TResponse> RunTaskWithAutoRetryOnQuotaLimitExceededError <TResponse>(Func <Task <TResponse> > action)
{
int retriesLeft = RetryCountOnQuotaLimitError;
int delay = RetryDelayOnQuotaLimitError;
TResponse response = default(TResponse);
while (true)
{
try
{
response = await action();
break;
}
catch (APIErrorException exception) when(exception.Response.StatusCode == (System.Net.HttpStatusCode) 429 && retriesLeft > 0)
{
ErrorTrackingHelper.TrackException(exception, "Face API throttling error");
if (retriesLeft == 1 && Throttled != null)
{
Throttled();
}
await Task.Delay(delay);
retriesLeft--;
delay *= 2;
continue;
}
}
return(response);
}
public static async Task ResetFaceLists()
{
faceLists = new Dictionary <string, FaceListInfo>();
try
{
IEnumerable <FaceList> metadata = await FaceServiceHelper.GetFaceListsAsync(FaceListsUserDataFilter);
foreach (var item in metadata)
{
await FaceServiceHelper.DeleteFaceListAsync(item.FaceListId);
}
}
catch (Exception e)
{
ErrorTrackingHelper.TrackException(e, "Error resetting face lists");
}
}
public async Task DetectFacesAsync(bool detectFaceAttributes = false, bool detectFaceLandmarks = false)
{
try
{
if (this.ImageUrl != null)
{
this.DetectedFaces = await FaceServiceHelper.DetectWithUrlAsync(
this.ImageUrl,
returnFaceId : true,
returnFaceLandmarks : detectFaceLandmarks,
returnFaceAttributes : detectFaceAttributes?DefaultFaceAttributeTypes : null);
}
else if (this.GetImageStreamCallback != null)
{
this.DetectedFaces = await FaceServiceHelper.DetectWithStreamAsync(
this.GetImageStreamCallback,
returnFaceId : true,
returnFaceLandmarks : detectFaceLandmarks,
returnFaceAttributes : detectFaceAttributes?DefaultFaceAttributeTypes : null);
}
if (this.FilterOutSmallFaces)
{
this.DetectedFaces = this.DetectedFaces.Where(f => IsFaceBigEnoughForDetection(f.FaceRectangle.Height, this.DecodedImageHeight));
}
}
catch (Exception e)
{
ErrorTrackingHelper.TrackException(e, "Face API DetectAsync error");
this.DetectedFaces = Enumerable.Empty <DetectedFace>();
if (this.ShowDialogOnFaceApiErrors)
{
await ErrorTrackingHelper.GenericApiCallExceptionHandler(e, "Face API failed.");
}
}
finally
{
this.OnFaceDetectionCompleted();
}
}
public static async Task Initialize()
{
faceLists = new Dictionary <string, FaceListInfo>();
try
{
IEnumerable <FaceList> metadata = await FaceServiceHelper.GetFaceListsAsync(FaceListsUserDataFilter);
foreach (var item in metadata)
{
faceLists.Add(item.FaceListId, new FaceListInfo {
FaceListId = item.FaceListId, LastMatchTimestamp = DateTime.Now
});
}
}
catch (Exception e)
{
ErrorTrackingHelper.TrackException(e, "Face API GetFaceListsAsync error");
}
}
public async Task FindSimilarPersistedFacesAsync()
{
this.SimilarFaceMatches = Enumerable.Empty <SimilarFaceMatch>();
if (this.DetectedFaces == null || !this.DetectedFaces.Any())
{
return;
}
List <SimilarFaceMatch> result = new List <SimilarFaceMatch>();
foreach (DetectedFace detectedFace in this.DetectedFaces)
{
try
{
SimilarFace similarPersistedFace = await FaceListManager.FindSimilarPersistedFaceAsync(this.GetImageStreamCallback, detectedFace.FaceId.GetValueOrDefault(), detectedFace);
if (similarPersistedFace != null)
{
result.Add(new SimilarFaceMatch {
Face = detectedFace, SimilarPersistedFace = similarPersistedFace
});
}
}
catch (Exception e)
{
ErrorTrackingHelper.TrackException(e, "FaceListManager.FindSimilarPersistedFaceAsync error");
if (this.ShowDialogOnFaceApiErrors)
{
await ErrorTrackingHelper.GenericApiCallExceptionHandler(e, "Failure finding similar faces");
}
}
}
this.SimilarFaceMatches = result;
}
public async Task IdentifyFacesAsync()
{
this.IdentifiedPersons = Enumerable.Empty <IdentifiedPerson>();
Guid[] detectedFaceIds = this.DetectedFaces?.Where(f => f.FaceId.HasValue).Select(f => f.FaceId.GetValueOrDefault()).ToArray();
if (detectedFaceIds != null && detectedFaceIds.Any())
{
List <IdentifiedPerson> result = new List <IdentifiedPerson>();
IEnumerable <PersonGroup> personGroups = Enumerable.Empty <PersonGroup>();
try
{
personGroups = await FaceServiceHelper.ListPersonGroupsAsync(PeopleGroupsUserDataFilter);
}
catch (Exception e)
{
ErrorTrackingHelper.TrackException(e, "Face API GetPersonGroupsAsync error");
if (this.ShowDialogOnFaceApiErrors)
{
await ErrorTrackingHelper.GenericApiCallExceptionHandler(e, "Failure getting PersonGroups");
}
}
foreach (var group in personGroups)
{
try
{
IList <IdentifyResult> groupResults = await FaceServiceHelper.IdentifyAsync(group.PersonGroupId, detectedFaceIds);
foreach (var match in groupResults)
{
if (!match.Candidates.Any())
{
continue;
}
Person person = await FaceServiceHelper.GetPersonAsync(group.PersonGroupId, match.Candidates[0].PersonId);
IdentifiedPerson alreadyIdentifiedPerson = result.FirstOrDefault(p => p.Person.PersonId == match.Candidates[0].PersonId);
if (alreadyIdentifiedPerson != null)
{
// We already tagged this person in another group. Replace the existing one if this new one if the confidence is higher.
if (alreadyIdentifiedPerson.Confidence < match.Candidates[0].Confidence)
{
alreadyIdentifiedPerson.Person = person;
alreadyIdentifiedPerson.Confidence = match.Candidates[0].Confidence;
alreadyIdentifiedPerson.FaceId = match.FaceId;
}
}
else
{
result.Add(new IdentifiedPerson {
Person = person, Confidence = match.Candidates[0].Confidence, FaceId = match.FaceId
});
}
}
}
catch (Exception e)
{
// Catch errors with individual groups so we can continue looping through all groups. Maybe an answer will come from
// another one.
ErrorTrackingHelper.TrackException(e, "Face API IdentifyAsync error");
if (this.ShowDialogOnFaceApiErrors)
{
await ErrorTrackingHelper.GenericApiCallExceptionHandler(e, "Failure identifying faces");
}
}
}
this.IdentifiedPersons = result;
}
this.OnFaceRecognitionCompleted();
}
public static async Task <SimilarFace> FindSimilarPersistedFaceAsync(Func <Task <Stream> > imageStreamCallback, Guid faceId, DetectedFace face)
{
if (faceLists == null)
{
await Initialize();
}
Tuple <SimilarFace, string> bestMatch = null;
bool foundMatch = false;
foreach (var faceListId in faceLists.Keys)
{
try
{
SimilarFace similarFace = (await FaceServiceHelper.FindSimilarAsync(faceId, faceListId))?.FirstOrDefault();
if (similarFace == null)
{
continue;
}
foundMatch = true;
if (bestMatch != null)
{
// We already found a match for this face in another list. Replace the previous one if the new confidence is higher.
if (bestMatch.Item1.Confidence < similarFace.Confidence)
{
bestMatch = new Tuple <SimilarFace, string>(similarFace, faceListId);
}
}
else
{
bestMatch = new Tuple <SimilarFace, string>(similarFace, faceListId);
}
}
catch (Exception e)
{
// Catch errors with individual face lists so we can continue looping through all lists. Maybe an answer will come from
// another one.
ErrorTrackingHelper.TrackException(e, "Face API FindSimilarAsync error");
}
}
if (!foundMatch)
{
// If we are here we didnt' find a match, so let's add the face to the first FaceList that we can add it to. We
// might create a new list if none exist, and if all lists are full we will delete the oldest face list (based on when we
// last matched anything on it) so that we can add the new one.
double maxAngle = 30;
if (face.FaceAttributes.HeadPose != null &&
(Math.Abs(face.FaceAttributes.HeadPose.Yaw) > maxAngle ||
Math.Abs(face.FaceAttributes.HeadPose.Pitch) > maxAngle ||
Math.Abs(face.FaceAttributes.HeadPose.Roll) > maxAngle))
{
// This isn't a good frontal shot, so let's not use it as the primary example face for this person
return(null);
}
if (!faceLists.Any())
{
// We don't have any FaceLists yet. Create one
string newFaceListId = Guid.NewGuid().ToString();
await FaceServiceHelper.CreateFaceListAsync(newFaceListId, "ManagedFaceList", FaceListsUserDataFilter);
faceLists.Add(newFaceListId, new FaceListInfo {
FaceListId = newFaceListId, LastMatchTimestamp = DateTime.Now
});
}
PersistedFace addResult = null;
bool failedToAddToNonFullList = false;
foreach (var faceList in faceLists)
{
if (faceList.Value.IsFull)
{
continue;
}
try
{
addResult = await FaceServiceHelper.AddFaceToFaceListFromStreamAsync(faceList.Key, imageStreamCallback, face.FaceRectangle);
break;
}
catch (Exception ex)
{
if (ex is APIErrorException && ((APIErrorException)ex).Response.StatusCode == (System.Net.HttpStatusCode) 403)
{
// FaceList is full. Continue so we can try again with the next FaceList
faceList.Value.IsFull = true;
continue;
}
else
{
failedToAddToNonFullList = true;
break;
}
}
}
if (addResult == null && !failedToAddToNonFullList)
{
// We were not able to add the face to an existing list because they were all full.
// If possible, let's create a new list now and add the new face to it. If we can't (e.g. we already maxed out on list count),
// let's delete an old list, create a new one and add the new face to it.
if (faceLists.Count == MaxFaceListCount)
{
// delete oldest face list
var oldestFaceList = faceLists.OrderBy(fl => fl.Value.LastMatchTimestamp).FirstOrDefault();
faceLists.Remove(oldestFaceList.Key);
await FaceServiceHelper.DeleteFaceListAsync(oldestFaceList.Key);
}
// create new list
string newFaceListId = Guid.NewGuid().ToString();
await FaceServiceHelper.CreateFaceListAsync(newFaceListId, "ManagedFaceList", FaceListsUserDataFilter);
faceLists.Add(newFaceListId, new FaceListInfo {
FaceListId = newFaceListId, LastMatchTimestamp = DateTime.Now
});
// Add face to new list
addResult = await FaceServiceHelper.AddFaceToFaceListFromStreamAsync(newFaceListId, imageStreamCallback, face.FaceRectangle);
}
if (addResult != null)
{
bestMatch = new Tuple <SimilarFace, string>(new SimilarFace {
Confidence = 1, PersistedFaceId = addResult.PersistedFaceId
}, null);
}
}
return(bestMatch?.Item1);
}