"Mounting" a background to the bottom of a control
===

I have a `UserControl` that has a repeating-image background set with the following code:

    <UserControl.Background>
        <ImageBrush ImageSource="Resources/image.jpg" Viewport="0,0,32,32" ViewportUnits="Absolute" TileMode="Tile" Stretch="None" AlignmentX="Left" AlignmentY="Top" />
    </UserControl.Background>

And it works fine. However, the problem is that the tiled images originate from the top of the control, so that if the control is resized vertically, the newly visible parts of the background seem to come out of the bottom of the control.

I would like the images to be tiled from the bottom to the top rather than the top to the bottom so that upon resizing the control, the newly visible background comes from the top, not the bottom

How can I do this? I have tried setting `AlignmentY` to `Bottom` but it didn't change a thing.