This used to be a command line only program, but now has a gui. My 1st conversion worked quite well. http://www.kvec.de/english/index.htm
Inkscape did not work well for me in converting a GIF file to dxf. I remembered this program KVEC from awhile back & found an updated version.
Here are the basics to get you started converting with this program.
Run the KVEC program & open an image file.
Click on Setttings, Parameter Settings/Settings 1 & change the Output format to DXF or whatever you require
There are quite a few other settings you can play with, but that is basically all you need to change to get started.
To convert the file to Vector, Click File/Convert
To save the output vector file, Click File/Save File
You will also need to scale the dxf file in Estlcam, Draftsight or some other means. I prefer to change it in Draftsight so I know the size of it before putting it in Estlcam. You can also change the scale in KVEC, but seems to be better output at its default of 1 pixel is 1mm.