Prevent image scaling on GridViewColumn entires?

I have a GridViewColumn created with the following XAML:

<GridViewColumn Header="Validated" >
  <GridViewColumn.CellTemplate>
    <DataTemplate>
      <Image Source="{Binding Path=Validated, Converter={StaticResource imageConverter}}" />
    </DataTemplate>
  </GridViewColumn.CellTemplate>
</GridViewColumn>

The images in the .png files created for display in the column are 13x13 pixels in size.

The images being displayed in the WPF form are being scaled to the display widt开发者_运维知识库h of the column, apart from any images displayed below the bottom of the visible area of the GridView, which show 13x13 pixel images.

What can I do to constrain the images in my GridView to 13x13 pixels and not to scale according to the column width?

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<Image Source="{Binding Path=Validated, Converter={StaticResource imageConverter}}" Stretch="None" />