I did something similar for a combination of a html/image box w/ the images in standard placement. Its not that hard. Use the ASP.NET image control for the image, the dnn URL control like this.
<dnn
:URL id="urlImage" runat="server" width="225" shownone="true" showtabs="False" showfiles="True" showUrls="True" urltype="F" showlog="False" shownewwindow="False" showtrack="False" />
You will have to do something like this for the loading of the image. There maybe a better way but I dunno how yet.
If ImageValFromDB.StartsWith("FileID=") Then
Dim _FileCont As New DotNetNuke.Services.FileSystem.FileController
Dim _FileInfo As DotNetNuke.Services.FileSystem.FileInfo
Dim _Id As Integer = CInt(Strings.Replace(ImageValFromDB, "FileID=", ""))
_FileInfo = _FileCont.GetFileById(_Id, Me.PortalId)
imgImage.ImageUrl = DotNetNuke.Common.ResolveUrl(Me.PortalSettings.HomeDirectory & _FileInfo.Folder & _FileInfo.FileName)
Else
imgImage.ImageUrl = ImageValFromDB
End If
If ImageValFromDB is empty, just set the visibility to false of the image control. Hope this helps.