internal RectangleScanner(Overlay overlay)
{
this.overlay = overlay;
rectangleRequest = new VNDetectRectanglesRequest(RectanglesDetected);
rectangleRequest.MaximumObservations = 10;
}
/// <summary>
/// Set Initial Condition
/// </summary>
public void ReadAndDisplayFirstFrame(bool performRectanglesDetection, out NSError error)
{
var videoReader = VideoReader.Create(this.videoAsset);
if (videoReader != null)
{
var firstFrame = videoReader.NextFrame();
if (firstFrame != null)
{
List <TrackedPolyRect> firstFrameRects = null;
if (performRectanglesDetection)
{
// Vision Rectangle Detection
var imageRequestHandler = new VNImageRequestHandler(firstFrame, videoReader.Orientation, new NSMutableDictionary());
var rectangleDetectionRequest = new VNDetectRectanglesRequest(null)
{
MinimumAspectRatio = 0.2f,
MaximumAspectRatio = 1f,
MinimumSize = 0.1f,
MaximumObservations = 10
};
imageRequestHandler.Perform(new VNRequest[] { rectangleDetectionRequest }, out NSError performError);
if (performError != null)
{
error = new VisionTrackerProcessorError(VisionTrackerProcessorErrorType.FirstFrameReadFailed);
return;
}
var rectObservations = rectangleDetectionRequest.GetResults <VNRectangleObservation>();
if (rectObservations != null && rectObservations.Any())
{
this.initialRectObservations = rectObservations.ToList();
var detectedRects = new List <TrackedPolyRect>();
for (var index = 0; index < this.initialRectObservations.Count; index++)
{
var rectangleObservation = this.initialRectObservations[index];
var rectColor = TrackedObjectsPalette.Color(index);
detectedRects.Add(new TrackedPolyRect(rectangleObservation, rectColor));
}
firstFrameRects = detectedRects;
}
}
error = null;
this.Delegate?.DisplayFrame(firstFrame, videoReader.AffineTransform, firstFrameRects);
}
else
{
error = new VisionTrackerProcessorError(VisionTrackerProcessorErrorType.FirstFrameReadFailed);
}
}
else
{
error = new VisionTrackerProcessorError(VisionTrackerProcessorErrorType.ReaderInitializationFailed);
}
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
// Configure UI
CameraButton.Enabled = UIImagePickerController.IsSourceTypeAvailable(UIImagePickerControllerSourceType.Camera);
GalleryButton.Enabled = UIImagePickerController.IsSourceTypeAvailable(UIImagePickerControllerSourceType.SavedPhotosAlbum);
// Setup Vision Rectangles
RectangleRequest = new VNDetectRectanglesRequest(HandleRectangles);
RectangleRequest.MaximumObservations = 10; // limit on the number of rectangles to look for - can increase "thinking time"
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
// Configure UI
CameraButton.Enabled = UIImagePickerController.IsSourceTypeAvailable(UIImagePickerControllerSourceType.Camera);
GalleryButton.Enabled = UIImagePickerController.IsSourceTypeAvailable(UIImagePickerControllerSourceType.SavedPhotosAlbum);
// Load the ML model
var bundle = NSBundle.MainBundle;
var assetPath = bundle.GetUrlForResource("MNISTClassifier", "mlmodelc");
var mlModel = MLModel.FromUrl(assetPath, out NSError mlErr);
var model = VNCoreMLModel.FromMLModel(mlModel, out NSError vnErr);
// Initialize
RectangleRequest = new VNDetectRectanglesRequest(HandleRectangles);
ClassificationRequest = new VNCoreMLRequest(model, HandleClassification);
}
