MrSid and ECW image format not recognized
When you open a drawing that contains MrSID or ECW images, only the image frame is displayed.
In addition, when you try to insert a MrSID or ECW image into a drawing using the_MAPIINSERT or _IMAGEATTACH command, neither MrSID nor ECW is listed as a valid raster image format.
To be able to view and insert MrSID or ECW raster images in AutoCAD® Civil 3D® or AutoCAD Map 3D with the _MAPIINSERT or the AutoCAD _IMAGEATTACH command, you need to download and install the AutoCAD Raster Design xxxx Object Enabler (where xxxx is the version of your product).
The object enablers for Autodesk products are available at the following location:
Autodesk Object Enablers