I remember when I had AutoCad, I could import a picture file, and it is possible to draw on top of it. A nice thing in Autocad was that this imported object was scaleable as all other objects, so it was easy to scale to correct scale. In D-Cad imported pictures cannot be scaled.
I wonder what will happen, if you have an AutoCad drawing, with a scanned picture/drawing of t.ex. other buildings, roads etc. and you save this AutoCad as DXF. Insert this in D-Cad - what will happen to the scanned image - will it become editable lines as other lines you draw??