I have a slightly strange request. I have access to a set of geo-ref'd PDFs that have multiple layers within the file. As touched on in other threads, there's no good way (at this time) to turn on/off layers from a PDF in QGIS. So I end up turning off/on the layers I want (in Acrobat) and then printing a new PDF file of the same size/resolution (however, the geo-reference metadata is lost when I print the new PDF).

So what I'd like to do, is import the geo-ref'd PDF into QGIS, export the CRS data, and then import the non-ref'd file and apply the CRS from the original file.

Can this be done? If so, how? And if you know how to control PDF layers within QGIS, let please let me know.

  • I may have incorrectly specified "CRS". I know how to apply the correct CRS, but what I can't figure out is how to apply the geo-ref "Extents" information (i.e. neatline polygon) to the new file. – Mark Jan 8 '18 at 18:54
  • I have managed to extract the projection from the good geo-ref'd pdf as a WLD file, but I can't figure out how to apply that projection to the non-ref'd file...I feel I'm so close! – Mark Jan 8 '18 at 19:38
  • I think you're looking for a way to get the world file information. That's a set of transformation parameters that "georeference" the raster. It's not the same as the CRS information, although the transformation parameters do convert the raw pixel numbers to CRS coordinates. – mkennedy Jan 8 '18 at 20:36

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