I have an image that is bigger than it's window container and it is placed in a ScrollViewer, however, the image does not scroll at all. I've tried putting the image in a container with no luck. What settings am I missing here? (I copied the code straight from MS, but they have it wrong)

Here's the code:

<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:h="http://helixtoolkit.codeplex.com"
x:Class="TileLayout"
Title="TileLayout" Height="1000"
Width="845" WindowStartupLocation="CenterScreen"
WindowStyle="ThreeDBorderWindow">
<StackPanel HorizontalAlignment="center"
VerticalAlignment="Top">
    <StackPanel
Orientation="Horizontal"   >
        <TextBox
x:Name="txtSourceFilePath" Width="500"
Margin="10" Height="22"
TextChanged="TextBoTextChanged"
Text="E:\projects\Test3D\SavedSnapshots\snapshot.png"/>
        <Button
x:Name="btnPickFile" Width="100"
Margin="0,10,10,10" Content="Pick File" ></Button>
   
</StackPanel>
    <ScrollViewer
VerticalScrollBarVisibility="Auto" >
        <Image
x:Name="imgFinal" Source="SteelMotion_chevron2.png"/>
   
</ScrollViewer>
</StackPanel>