CVUwpMainPageWebCamAndOnnx.cs

CVUwpMainPageWebCamAndOnnx.cs

protected override async void OnNavigatedTo(NavigationEventArgs e)
{
    InitModel();
    await CameraPreview.StartAsync();
    CameraPreview.CameraHelper.FrameArrived += CameraHelper_FrameArrived;
}

private async void CameraHelper_FrameArrived(object sender, Microsoft.Toolkit.Uwp.Helpers.FrameEventArgs e)
{
    if (e.VideoFrame.SoftwareBitmap == null) return;
    try
    {
        if (_objectDetection?.Model == null) return;
        await LoadAndEvaluateModelAsync(e.VideoFrame);
    }
    catch (Exception exception)
    { Debug.WriteLine(exception); }
}

private ObjectDetection _objectDetection;

private async void InitModel()
{
    _objectDetection = new ObjectDetection();
    var modelFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri($"ms-appx:///Assets/model.onnx"));
    await _objectDetection.Init(modelFile);
}

private async Task LoadAndEvaluateModelAsync(VideoFrame videoFrame)
{
    var result = await _objectDetection.PredictImageAsync(videoFrame);
    var message = $"{DateTime.Now.ToLongTimeString()}{Environment.NewLine}============================={Environment.NewLine}";
    message = result.Aggregate(message, (current, predictionModel) => current + $" {predictionModel.TagName} {(predictionModel.Probability * 100.0f):#0.00}% {Environment.NewLine}");
    Debug.WriteLine(message);
}