http://rkmcswain.blogspot.com/2005/04/binding-raster-images.html
@unknownuser said:
So what's this article about? You probably came here because you want to "bind" a raster image. Here are a few ways:
Insert the image as an OLE object
[*] In AutoCAD, run the INSERTOBJ command. [*] Choose "Create New", then choose "Bitmap Image". [*] Next, Windows Paintbrush should open up. [*] In Paintbrush, choose the Edit menu, then PasteFrom [*] Select your existing image file (JPG, BMP, PNG, TIF, etc.) [*] While still in Paintbrush, choose File, then Exit and Return to AutoCAD
Use the IMAGE BIND command in Dotsoft ToolPac. This command reads the image (either an image on disk, or one that exists in the drawing) and creates AutoCAD geometry to represent the image.
Use an standalone program such as Img2CAD. This program will accept most raster images as input, and then output one of the following: DXF, EMF, WMF or HPGL. I tested a 132,000,000 pixel TIFF file and converted it to a DXF. Depending on the options selected, the output DXF was anywhere from 52MB to 96MB in size. Quite large, but the program was able to perform the conversion in about a minute. Not bad for such a large image.
If you know about other options, let me know.
UPDATE:Raster Design 2008 allows you to embed (or bind) an IMAGE into a DWG. See this post for more details.