[Inkscape-user] grayscale to s-code ngc

Hi,

I'm building a laser engraver. I'd like to engrave grayscale pictures. To build the ngc-file I'm using inkscape ( what else ). The graffiti/ spraygun option in Gcodetools seems the right choice. Nevertheless grayscale is not translated to S-values. I need these values because my laser uses the spindle speed as reference for its intensity.

Does anyone know where I can find documentation/ solution concerning this issue ?

Greetings,

René.