async void UploadAndDetectFaces(string imageFilePath) { try { StorageFolder appInstalledFolder = Windows.ApplicationModel.Package.Current.InstalledLocation; StorageFolder assets = await appInstalledFolder.GetFolderAsync("Assets"); var storageFile = await assets.GetFileAsync(imageFilePath); var randomAccessStream = await storageFile.OpenReadAsync(); using (Stream stream = randomAccessStream.AsStreamForRead()) { // This is the fragment where the face is recognized: var faces = await faceServiceClient.DetectAsync(stream); var faceRects = faces.Select(face => face.FaceRectangle); _faceRectangles = faceRects.ToArray(); // Forces a redraw on the canvas control CustomCanvas.Invalidate(); } } catch (Exception ex) { System.Diagnostics.Debug.WriteLine(ex.Message); } }