Write A Custom Rendering Template For The DisplayForm?

I'm trying to write a custom rendering template for use in the DisplayForm of a list whose fields include Title, HeaderImageUrl, Body. I've got the following so far:

<SharePoint:RenderingTemplate ID="NewsListForm" runat="server">
<Template>
<h1><SharePoint:FieldValue FieldName="Title" runat="server"/></h1>
<div>
<p>
<SharePoint:UrlField FieldName="HeaderImageUrl" runat="server"></SharePoint:UrlField>
<SharePoint:RichTextField FieldName="Body" runat="server" />
</p>
</div>
</Template>
</SharePoint:RenderingTemplate>

The HeaderImageUrl field is configured to be an Image URL, but when I use the UrlField control, it renders a link.

I was thinking there might be a way to grab field values and put them in attributes, so something like this:

<asp:Image ImageUrl="<% FieldValue["HeaderImageUrl"] %>" runat="server"/>

If this kind of thing isn't possible, then is there another control in Microsoft.SharePoint.WebControls that would render an image from a URL?