Migrating a project from ArcGIS to QGIS: Georeferenced PDFs

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I hate to even say “GeoPDF”. It’s not a bad thing. Much like saying “Mr Sid” I probably do it with a contorted facial expression.

If you’ve kept up I’ve been slowly moving this project from ArcGIS to QGIS and it’s almost done. There are still a few processes I’m trying to work out with the client but it’s nothing more than a lack of understanding on my part. There are two hurdles left on my end though: Geodatabases and GeoPDFs.

I developed (for me) a fairly complicated map document that has been exported out of QGIS and delivered to the client’s client. The client’s client ended up being (and I had no clue) field personnel that didn’t want QGIS/ArcGIS/Complicated. So as part of the delivery I*needed to provide GeoPDF’s. *I haven’t been. Well – I remembered and here we go.

If you’re working in ArcGIS you can export a PDF with “georeference information” attached. It also has layer information so you can click and do things with the PDF through acrobat reader and extract information. ArcGIS has*had that ability for quite some time. There really isn’t an open source alternative to this functionality. You’re just stuck if you’re looking for a button click solution.

After doing some digging here is what I came up with. You can make a Georeferenced PDF out of QGIS. It’s a four*step process.

  1. In your QGIS Composer document You need to make one change on the composer tab:


2. Then you want to export your document as a tif file. Yes you are making a georeferenced tif. I know.

Now from command line you get run two commands.

  • The first command makes your tif with a tfw file a geotiff: gdal_edit.py -a_srs EPSG:2274 output.tif*
  • The next and final command gives you a georeferenced pdf: gdal_translate -of PDF output.tif output.pdf*
What if you have a pile of them to do? Learn some scripting. I created a bash script (have I mentioned I’m doing this all on linux) and exported everything to a pdf.

Pros:

  • I’m still doing all of this for free in easily accessible software
  • There are a lot of options for making Geospatial PDF’s from GDAL ->*http://www.gdal.org/frmt_pdf.html
Cons:

  • You have to drift back to command line and I’m debating how to explain this to submit a enhancement to the QGIS*group. It may be already.
  • It’s not a true “GeoPDF”. I consider this a georeferenced PDF. We have none of the enhancements from Terrago
  • File size is a bit large and I really need to play with resolution and a few other things. Right now I’m in a 8mb range for an output.
  • There are a lot lot of options for making Geospatial PDF’s from GDAL ->*http://www.gdal.org/frmt_pdf.html
BUT – it’s works with their software and the client is happy for now. So I’m left with one last hurdle: geodatabases. I know what to do there – I just need to sit down for a bit and do it.









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