Autocad Raster Design 2013, Windows 7 Ultimate. I need a bitonal image to use in raster design, but the images I have tried will not work. I have used the IDEPTH command and hit B for Bitonal, but the image is still invalid. I realized that all of the images I had processed before I had sent through the scanner and it gave me a bitonal image. Now that I need to use it on an existing .jpg, I can't get there. So what exaclty is the format of a bitonal image? When I want to create an image type that will automatically work in Map, what is that file type? And why doesn't the IDEPTH command do it?