Background Blur

Landscape.jpg

Main.xaml

<Grid
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <Grid x:Name="Layers">

    <Grid x:Name="BackgroundPanels">
      <Image Source="Landscape.jpg" Stretch="UniformToFill"/>
    </Grid>

    <Grid x:Name="BlurredPanel">
      <Border HorizontalAlignment="Left" VerticalAlignment="Top" Margin="100,400,0,0">
        <Grid>
          <Border Opacity="0">
            <Rectangle x:Name="blur" Width="600" Height="300">
              <Rectangle.Fill>
                <VisualBrush Visual="{Binding ElementName=BackgroundPanels}" ViewboxUnits="Absolute" Viewbox="100,400,600,300"/>
              </Rectangle.Fill>
              <Rectangle.Effect>
                <BlurEffect Radius="20"/>
              </Rectangle.Effect>
            </Rectangle>
          </Border>
          <Ellipse Width="600" Height="300" Stroke="Black" StrokeThickness="1">
            <Ellipse.Fill>
              <VisualBrush Visual="{Binding ElementName=blur}" ViewboxUnits="Absolute" Viewbox="0,0,600,300"/>
            </Ellipse.Fill>
          </Ellipse>
          <Button Content="Button" HorizontalAlignment="Center" VerticalAlignment="Center"/>
        </Grid>
      </Border>
    </Grid>

  </Grid>

</Grid>