Importing PDF JOSM

pdfimport is very powerful tool, but requires some learning and experimenting to get to grips with. Also, unfortunately, as of now, it has virtually no documentation. Here's quick-ish guide:

First, you'll need a PDF that

• You're legally allowed to use in OpenStreetMap
• Is in a known coordinate system
• Preferably has coordinate grid with labels

Also you might need to tweak your JOSM setup too. pdfimport tends to use a lot of RAM, and you can run out of memory with more complex PDFs. Arrange so that your system has several gigs of RAM, and launch JOSM with "Xmx" option, like this "java -Xmx1024M -jar josm-latest.jar". You can put that command in .sh or .bat file for convenience.

So, this is how you import PDF in separate layer in JOSM:

• Open the pdfimport plugin from "Tools - Import PDF file"
• Optionally tweak some settings in "Import settings" groupbox. The options there deal with filtering imported PDF data. If there's lots of garbage vector data in PDF file (like, lines used for creating fill patterns), tinkering with these options can turn import process and subsequent operations from unbearably slow to reasonably quick
• Press on "Load file" , select your PDF
• Select correct projection
• The hardest part: georeference PDF by specifying coordinates for two reference points. Here coordinate grid comes in handy. Say, for bottom left corner:
• Select a point somewhere in bottom left part of PDF file that is precisely on intersection of horizontal and vertical coordinate lines (sorry, don't know the right lingo)
• Press on "Take X and Y from sel..." to fill "PDF X and Y" fields
• Read coordinates for this point from PDF, and put them in "East and North" boxes. The measurement units for these are in meters, but coordinate grid is sometimes labelled with km's so you may need to multiply the numbers by 1000. Here's an illustration of where numbers end up:

• With coordinates and coordinate system in place, you're good to go. If you press "Show target", JOSM will place viewport over the region where PDF data will end up, useful for checking that you didn't mix up the numbers and your data is not going to appear on the other side of globe...
• Press "Place", this will load vector data from PDF file into a separate JOSM data layer

What happens next? Most likely imported PDF data is noisy and dirty, and requires some cleaning and tagging before it's good to upload. The best way to do this is to work in separate layers--select some stuff in your PDF layer, copy it to OSM layer, then clean up tags, fix overlapping issues etc. Importer adds a bunch of tags to imported nodes and ways, these are handy for semi-automating the cleanup process. The "Search" function in "Selection" panel is your friend!

If you haven't done this yet, you have to download the plugin "pdfimport" You can do this by going to Edit - Preferences - Plugins then click on "Download List" on the bottom. After a restart of JOSM you can use the plugin by going to Tools - Import PDF File A new window opens where you can select different settings.

Could you not use a map warper program and simply use the resulting co-ordinates to make it a background image?

So, I've installed pdfimport with the idea using a pdf as a guiding layer to fix osm data. Not quite sure if that's what you had in mind. But...

First problem: There is no "Tools - Import PDF file"

Is pdfimport maintained and up-to-date?

The pdf in question (5.5M): http://www.dot.state.mn.us/metro/projects/hwy100slp/pdf/projectmap.pdf

Permission to use granted at www.dot.state.mn.us/information/disclaimer.html section "Maps and related data".