Even with Dispatcher.Invoke: The calling thread cannot access this object because a different thread owns it

Question

i'm stucked at some point which seemed to be easy....

I have a View with an image control:

 <Image x:Name="ImageControl" Source="{Binding DisplayedImage, UpdateSourceTrigger=PropertyChanged }" HorizontalAlignment="Left" 
    Margin="0,0,0,0" Stretch="Fill" VerticalAlignment="Bottom" 
     Width="800" Height="300" Grid.Column="3" Grid.Row="3" />

And creating the Datacontext in the background :

public MainWindow()
        {
            InitializeComponent();
            MainViewModel VM = new MainViewModel();
            
            ImageControl.DataContext = VM;
        }

In my Viewmodel i have the property as well as doing something on the backgroundworker. In the backgroundworker i raise an event and the event handler should update the property which should result in an update of the image:

public event EventHandler<NewImageToShowEventArgs> NewImageToShowEvent;

        public class NewImageToShowEventArgs : EventArgs
        {
            public BitmapSource NewImage { get; set; }
            public Bitmap NewImage2 { get; set; }

        }

 public MainViewModel()
        {
            uiScheduler = TaskScheduler.FromCurrentSynchronizationContext();
            int Result = GetCamera();
            //MessageBox.Show(Convert.ToString( Result));
            // Assign Each Task with GrabImage helper
            
            Grabbgw.DoWork += DoGrab;
           // Grabbgw.RunWorkerCompleted += GrabWorkerCompleted;
            bgws.Add(Grabbgw);
            

            //assign Events
            NewImageToShowEvent += NewImageToShow;
            StartGrab();
        }
 private void NewImageToShow(object sender, NewImageToShowEventArgs e)
        {
            try
            {
                Application.Current.Dispatcher.Invoke((new Action(() =>
                {
                    //DisplayedImage.Freeze(); // through a different error
                    DisplayedImage = e.NewImage.Clone();
                   // DisplayedImage2 = e.NewImage2;
                })));
                //Task.Factory.StartNew(() => DisplayedImage2 = e.NewImage2, CancellationToken.None, TaskCreationOptions.None, uiScheduler);
                //App.Current.MainWindow.Dispatcher.BeginInvoke(new Action(() =>
                //{

                //    DisplayedImage = e.NewImage.Clone();
                //    DisplayedImage2 = e.NewImage2;
                //}));
            }
            catch (Exception ex) {
                MessageBox.Show(ex.Message);
            }

        }
 NewImageToShowEventArgs  args = new NewImageToShowEventArgs();
                            args.NewImage = rawImage.bitmapsource.Clone() ;
                            args.NewImage2 = rawImage.bitmap;
                            NewImageToShowEvent?.Invoke(this, args);

I tried several things but all results in: "The calling thread cannot access this object because a different thread owns it." I searched now for hours without any results. I mean i tried the suggestions but they doesn't solved the problem. General Info: I get the image from a camera as either Bitmap or BitmapSource.

In the Output window it shows additional errors:

Exception thrown: 'System.InvalidOperationException' in WindowsBase.dll Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll

I hope somebody has an idea why i still get the error.

Thanks!

All the best, Jan