public async Task CapturePhoto()
{
await webcam.InitializeCameraAsync();
if (!webcam.IsInitialized())
{
Debug.WriteLine("Not initialied");
}
StorageFile image = await webcam.CapturePhoto();
try
{
// Oxford determines whether or not the visitor is on the Whitelist and returns true if so
recognizedVisitors = await OxfordFaceAPIHelper.IsFaceInWhitelist(image);
}
catch (FaceRecognitionException fe)
{
switch (fe.ExceptionType)
{
// Fails and catches as a FaceRecognitionException if no face is detected in the image
case FaceRecognitionExceptionType.NoFaceDetected:
Debug.WriteLine("WARNING: No face detected in this image.");
break;
}
}
catch (FaceAPIException faceAPIEx)
{
Debug.WriteLine("FaceAPIException in IsFaceInWhitelist(): " + faceAPIEx.ErrorMessage);
}
catch
{
// General error. This can happen if there are no visitors authorized in the whitelist
Debug.WriteLine("WARNING: Oxford just threw a general expception.");
}
if (recognizedVisitors.Count > 0)
{
// If everything went well and a visitor was recognized, unlock the door:
Ledpin.Write(GpioPinValue.Low);
}
else
{
// Create or open the folder in which the Whitelist is stored
StorageFolder folder = await KnownFolders.PicturesLibrary.CreateFolderAsync("Banned", CreationCollisionOption.OpenIfExists);
// Move the already captured photo the user's folder
await image.MoveAsync(folder);
var model = new Models.Database.Ban()
{
Image = image.Name,
Time = DateTime.Now
};
Ledpin.Write(GpioPinValue.High);
database.InsertModel <Models.Database.Ban>(model);
}
isCapturing = false;
}
/// <summary>
/// Called when user hits physical or vitual doorbell buttons. Captures photo of current webcam view and sends it to Oxford for facial recognition processing.
/// </summary>
private async Task DoorbellPressed()
{
// Display analysing visitors grid to inform user that doorbell press was registered
AnalysingVisitorGrid.Visibility = Visibility.Visible;
// List to store visitors recognized by Oxford Face API
// Count will be greater than 0 if there is an authorized visitor at the door
List <string> recognizedVisitors = new List <string>();
// Confirms that webcam has been properly initialized and oxford is ready to go
if (webcam.IsInitialized() && initializedOxford)
{
// Stores current frame from webcam feed in a temporary folder
StorageFile image = await webcam.CapturePhoto();
try
{
// Oxford determines whether or not the visitor is on the Whitelist and returns true if so
recognizedVisitors = await OxfordFaceAPIHelper.IsFaceInWhitelist(image);
}
catch (FaceRecognitionException fe)
{
switch (fe.ExceptionType)
{
// Fails and catches as a FaceRecognitionException if no face is detected in the image
case FaceRecognitionExceptionType.NoFaceDetected:
Debug.WriteLine("WARNING: No face detected in this image.");
break;
}
}
catch (FaceAPIException faceAPIEx)
{
Debug.WriteLine("FaceAPIException in IsFaceInWhitelist(): " + faceAPIEx.ErrorMessage);
}
catch
{
// General error. This can happen if there are no visitors authorized in the whitelist
Debug.WriteLine("WARNING: Oxford just threw a general expception.");
}
if (recognizedVisitors.Count > 0)
{
// If everything went well and a visitor was recognized, unlock the door:
AuthenticateUser(recognizedVisitors[0]);
}
else
{
// Otherwise, inform user that they were not recognized by the system
await speech.Read(SpeechContants.VisitorNotRecognizedMessage);
}
}
else
{
if (!webcam.IsInitialized())
{
// The webcam has not been fully initialized for whatever reason:
Debug.WriteLine("Unable to analyze visitor at door as the camera failed to initlialize properly.");
await speech.Read(SpeechContants.NoCameraMessage);
}
if (!initializedOxford)
{
// Oxford is still initializing:
Debug.WriteLine("Unable to analyze visitor at door as Oxford Facial Recogntion is still initializing.");
}
}
doorbellJustPressed = false;
AnalysingVisitorGrid.Visibility = Visibility.Collapsed;
}
