Let’s say I wanted to carve a shallow 1/8" groove everywhere there is a black line in this image? I have Photoshop and Inkscape but so far all of my png → svg conversion attempts have been a mess. I would appreciate some guidance on which tools in those massive applications to use and how to use them.
Dave
Edge Detection is the thing you need here.
I can’t remember what Photoshop can do, but there should be online pages that will likely let you run an edge detection routine over an image if not.
You’ll probably need to smooth / post-process the output with some thresholding / smoothing to get it nice, then convert it to an SVG as a final step.
Edge detection ( Edge detection - Wikipedia )
is a subset of feature detection (Feature (computer vision) - Wikipedia)
is a branch of Computer Vision (Computer vision - Wikipedia )
If you’re interested in some background 
Carbide create has a tool for doing this (its not free though)
Here’s what the traced image looks like in that case. It’s not exactly the cleanest file
Version 6 is still free, though unsupported. I still use it tons.
I have used Inkscape multiple times even with tricky pictures and I was always able to isolate the contour of certain objects in inkscape by tracing the bitmap using edge detection. There are even ways to smoothen the polyline that is created in the process. Hope that helps
