The customer sends me a picture and using Corel Draw I make the DXF file. I use the bezier tool for that.
Then the DXF is imported into SheetCam. SheetCam makes the TAP file (g-code).
Then open the TAP file in Mach3 and the table cuts it out.
So there is no magic program that turns a photograph into g-code. It's graphic design with Corel and SheetCam.