I am trying to use the tracer to convert this to a vector format: http://daviddoria.com/Uploads/map.png . The only settings in the "Mode" tab that I can get to work produce double lines (on either side of the lines in the bitmap). Can anyone tell me how to trace this but make the vector lines be produced where the bitmap lines are?

Thanks,

David

daviddoria wrote:Can anyone tell me how to trace this but make the vector lines be produced where the bitmap lines are?

Inkscape uses an embedded version of potrace for the tracing. potrace does not support centerline tracing (which is what you are asking for, as far as I understand). Consider using autotrace for this task (while the program is quite old and hasn't seen any recent updates, it seems to be the only open-source tool that can do centerline tracing). There's also a web interface available (in case you can't easily install it on your platform, or don't feel comfortable using the command-line interface).

Just fyi here are some sample results that I did with Inkscape's Trace Bitmap. I didn't get any double lines, so it may be just not having the settings right. Or if you used multiple scans, maybe one of them got moved over slightly, making the lines appear to be double?

Clearly below, the Brightness Cutoff option gives the best results. And I did not try the ROIT's centerline trace option, but you could do your own comparison (I have used the ROIT Systems' tracer in the past, with good results, but haven't used the Centerline option.)
These are shown at 50% zoom:

Also please note that the Update feature of the Trace Bitmap dialog does not work for the Brightness Cutoff option. But the actual trace (OK) does work -- you just have to trace and undo, in place of update).

brynn wrote:I didn't get any double lines, so it may be just not having the settings right.

Hi Brynn, I think David means that the trace in Inkscape yields filled rather than stroked lines. Change your view to outline mode, zoom in to one of the lines and see if you see a 'double' line...

Oh, interesting!
Thanks druban, I did not realize this

And sorry daviddoria, my examples won't work either