Draw a connection line between two elements in pure XAML - wpf

Question

I'm very very new to WPF and XAML.
I've two Image elements placed on a 4x4 Grid (say x:Name='LHImage' x:Name='RHImage) and and I would like to connect them with a line.
Something like this:
<Line
X1="{Binding ElementName=LHImage, Path=RenderedBoundingRect.Right}"
Y1="{Binding ElementName=LHImage, Path=RenderedBoundingRect.Middle}"
X2="{Binding ElementName=RHImage, Path=RenderedBoundingRect.Left}"
Y2="{Binding ElementName=RHImage, Path=RenderedBoundingRect.Middle}"
Stroke="Gray"
StrokeThickness="5" Grid.ColumnSpan="4" Grid.RowSpan="4"/>
Of course RenderedBoundingRect and its Left Right Middle properties don't exist and should be replaced by some other expression that it's just what I'm looking for.
Is that possible in pure XAML (no C# side code)?
EDIT:
As requested here is a screenshot of the desired result:

Answer 1

If you put all your controls in the same container (like a Canvas) you could do it with some tricks:
<Canvas>
<Rectangle Height="30" Width="50" Fill="Red">
<Rectangle.RenderTransform>
<TransformGroup>
<!--Bound transform or absolute transform-->
<TranslateTransform x:Name="LHImage" X="80" Y="50"/>
<!--Relative transform-->
<TranslateTransform X="-50" Y="-15"/>
</TransformGroup>
</Rectangle.RenderTransform>
</Rectangle>
<Rectangle Height="30" Width="50" Fill="Red">
<Rectangle.RenderTransform>
<TransformGroup>
<TranslateTransform x:Name="RHImage" X="130" Y="20"/>
<TranslateTransform X="0" Y="-15"/>
</TransformGroup>
</Rectangle.RenderTransform>
</Rectangle>
<Line
X1="{Binding ElementName=LHImage, Path=X}"
Y1="{Binding ElementName=LHImage, Path=Y}"
X2="{Binding ElementName=RHImage, Path=X}"
Y2="{Binding ElementName=RHImage, Path=Y}"
Stroke="Gray"
StrokeThickness="5"/>
</Canvas>
But if you use a Grid and put your controls in different cells, then you would have to sum some dimensions which is impossible without a simple Converter.
So, I would say it's nearly impossible to do without code behind, but the required code can be very short and clear.