Image to DXF Converter & DXF to G-Code Converter

I am in the research process of building a CNC Plasma Cutter. From a
Software aspect, I need a software to convert an image file, such as
JPEG or BMP, into a DXF file to be inputted into I_Deas CAD software.
I am also in need of a software that converts a DXF file into G&M Code
to be inputted into the controller. I wasn't sure if there's such a
software available, or will I have to write a post-processor to do the
job for me? Cost is not an issue at the moment, because I am currently
just comparing different software packages.
I'd appreciate any suggestions or personal experiences.
Anne