Embroidery designs can be created from both bitmap and vector graphics, although vectors are preferred options.
Nevertheless, even bitmaps are doable and thus you should be able to convert WMF graphics (Windows Metafile) to Janome layout file (.jef) for example, via wmf to jef conversion.
You will just need a program that offers so called digitizing function, i.e. function that will allow you to convert bitmap to embroidery design.