CVOnnxWin10DrawFrames.cs

CVOnnxWin10DrawFrames.cs

private async Task LoadAndEvaluateModelAsync(VideoFrame videoFrame)
{
    _objectDetection.ProbabilityThreshold = 0.5F;
    _stopwatch = Stopwatch.StartNew();
    _predictions = await _objectDetection.PredictImageAsync(videoFrame);
    _stopwatch.Stop();
    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        DrawFrames();
    });
}

private void DrawFrames()
{
    OverlayCanvas.Children.Clear();
    var message = $"{DateTime.Now.ToLongTimeString()} - {1000f / _stopwatch.ElapsedMilliseconds,4:f1} fps{Environment.NewLine}============================={Environment.NewLine}";
    if (_predictions.Count > 0)
        foreach (var prediction in _predictions)
            DrawFrame(prediction, OverlayCanvas);
    TextBlockResults.Text = message;
}

private void DrawFrame(PredictionModel prediction, Canvas overlayCanvas)
{
    _overlayCanvasActualWidth = (uint)CameraPreview.ActualWidth;
    _overlayCanvasActualHeight = (uint)CameraPreview.ActualHeight;

    var x = (uint)Math.Max(prediction.Box.Left, 0);
    var y = (uint)Math.Max(prediction.Box.Top, 0);
    var w = (uint)Math.Min(_overlayCanvasActualWidth - x, prediction.Box.Width);
    var h = (uint)Math.Min(_overlayCanvasActualHeight - y, prediction.Box.Height);

    Debug.WriteLine($"\tOverLay Canvas \tActual Width: {_overlayCanvasActualWidth}, Actual Height: {_overlayCanvasActualHeight}");
    Debug.WriteLine(prediction.GetExtendedDescription());
    Debug.WriteLine($"\tOriginal\tY: {y}, x: {x}, Height: {h}, Width: {w}");

    // fit to current size
    var factorSize = 100u;
    x = _overlayCanvasActualWidth * x / factorSize;
    y = _overlayCanvasActualHeight * y / factorSize;
    w = _overlayCanvasActualWidth * w / factorSize;
    h = _overlayCanvasActualHeight * h / factorSize;

    Debug.WriteLine($"\tScaled\tY: {y}, x: {x}, Height: {h}, Width: {w}");

    var rectStroke = _lineBrushGreen;
    switch (prediction.TagName)
    {
        case "Venom":
            rectStroke = _lineBrushGray;
            break;
        case "Rocket_Racoon":
            rectStroke = _lineBrushYellow;
            break;
        case "Iron_Fist":
            rectStroke = _lineBrushGreen;
            break;
    }

    var r = new Windows.UI.Xaml.Shapes.Rectangle
    {
        Tag = prediction,
        Width = w,
        Height = h,
        Fill = _fillBrush,
        Stroke = rectStroke,
        StrokeThickness = _lineThickness,
        Margin = new Thickness(x, y, 0, 0)
    };

    var tb = new TextBlock
    {
        Margin = new Thickness(x + 4, y + 4, 0, 0),
        Text = $"{prediction}",
        FontWeight = FontWeights.Bold,
        Width = 126,
        Height = 21,
        HorizontalTextAlignment = TextAlignment.Center
    };

    var textBack = new Windows.UI.Xaml.Shapes.Rectangle
    {
        Width = 150,
        Height = 29,
        Fill = rectStroke,
        Margin = new Thickness(x, y, 0, 0)
    };

    overlayCanvas.Children.Add(textBack);
    overlayCanvas.Children.Add(tb);
    overlayCanvas.Children.Add(r);
}