/// <summary>
/// Detect face and return the face id of a image file
/// </summary>
/// <param name="imageFile">
/// image file to detect face
/// </param>
/// <returns>face id</returns>
private async Task <Guid[]> DetectFacesFromImage(StorageFile imageFile)
{
var stream = await imageFile.OpenStreamForReadAsync();
var faces = await _faceApiClient.DetectAsync(stream);
if (faces == null || faces.Length < 1)
{
throw new FaceRecognitionException(FaceRecognitionExceptionType.NoFaceDetected);
}
return(FaceApiUtils.FacesToFaceIds(faces));
}
public async Task <Dictionary <HSFace, HSPerson> > FaceRecognizeAsync(StorageFile imageFile)
{
var recogResult = new Dictionary <HSFace, HSPerson>();
if (!FaceApiUtils.ValidateImageFile(imageFile))
{
throw new FaceRecognitionException(FaceRecognitionExceptionType.InvalidImage);
}
// detect all faces in the image
var arFaces = await DetectFacesFromImage(imageFile);
// try to identify all faces to person
var identificationResults = await FaceServiceHelper.IdentifyAsync(WhitelistId, FaceApiUtils.FacesToFaceIds(arFaces));
// add identified person name to result list
foreach (var result in identificationResults)
{
if (result.Candidates.Length > 0)
{
var person = _whitelist.GetPersonById(result.Candidates[0].PersonId);
Debug.WriteLine(String.Format("Detected person {0} face ID Confidence: {1}% image file: {2}",
person.Name, Math.Round(result.Candidates[0].Confidence * 100, 1), imageFile.Path));
recogResult.Add(new HSFace(result.FaceId, imageFile.Path), person);
}
else
{
foreach (ClientContract.Face detectedFace in arFaces)
{
if (detectedFace.FaceId == result.FaceId)
{
recogResult.Add(new HSFace(result.FaceId, imageFile.Path, detectedFace.FaceAttributes), null);
Debug.WriteLine(String.Format("Unknown {0} age {1} face ID {2} image file: {3}", detectedFace.FaceAttributes.Gender,
detectedFace.FaceAttributes.Age, detectedFace.FaceId, imageFile.Path));
}
}
}
}
return(recogResult);
}