Help with binding in WPF

<Image Source="sourceHere" Stretch="Uniform" Width="100" Height="100">
    <Image.ToolTip>
        <Image Source="{Binding thisImage.Source}" Stretch="Uniform" />
    </Image.ToolTip>
</Image>

the parent image is a 开发者_Go百科thumbnail of a bitmap, but I want the tooltip to show the image with 100% size.

How can I bind the image within the tooltip to the parent's source?

<Image x:Name="thisImage" Source="sourceHere" Stretch="Uniform" Width="100" Height="100">
    <Image.ToolTip>
        <Image Source="{Binding ElementName=thisImage, Path=Source}" Stretch="Uniform" />
    </Image.ToolTip>
</Image>

should do it