Engraving a B/W image with a drag bit.

I have been experimenting with drag bits for the past week or so. I went from only lines, to filling some areas. But now I'd like to engrave a full grayscale image with it. What I think I need is a way of converting the different shades, to different line densities (like in the attachment), but all I've found are ways to engrave with varying depths.
As a second option I would go for something like laser engraving only full black and full white as stated by the user "ClayJar" on the below link.
https://community.carbide3d.com/t/fi...ag-bit/7616/14

Any thoughts?