Currently when writing raster data to the AutoCAD formats, images are written as .png to the same directory as the output .dwg, with the same name as the output .dwg.
It is also not currently possible to create points with an external reference to an image using the autocad_xref_path format attribute. (Otherwise you could add a separate image writer and use this).
It would be useful to be able to chose the format, name and write location of images alongside .dwg output.
