> My view of how it should be, and my experience, is that the input file > to the georeferencer generally does not have a CRS.
My JPEG image came with a .jgw which is supposed to georeference it, but there was no CRS. Through trial and error I found setting (not reprojecting) the CRS to EPSG:3857 got it close, but it was still 1 km or so off the correct position, so I wanted to georeference it myself to get it more precise, but this is what kept producing the error. When I tried to georeference it without this .jgw file it finished the process, but loading the resulting georeferenced file resulted in strange behaviour - the image was rendered a few thousand kilometres away from the points I'd selected in the georeferencer. I've never had that happen before, usually the points I pick in the georeferencer match very closely to the points I indicated on the main map. My workaround was: 1. Add the JPEG (with the .jgw file present) as a new layer. 2. Change "Invalid CRS" to EPSG:3857 in the layer properties, Source tab. 3. Export to a GeoTIFF, using EPSG:3857 or the project CRS (doesn't seem to matter which, it seems to reproject the raster?) 4. Georeference the exported GeoTIFF file instead of the original JPEG. It seems something fishy is going on with the original JPEG and .jgw file, but once I've converted it to a GeoTIFF then the georeferencer seems to be able to handle it correctly. > I can't parse "set the CRS to" This is going into the layer properties and on the Source tab, changing the Assigned CRS to another value (per step 2 above). It defaults to "Invalid CRS" when I load the JPEG with the .jgw present in the same folder. > and "reprojected it to". This is exporting the layer to another file, and selecting a different CRS for the export, per step 3 above. > I'm guessing there is a bug that your case is triggering and that you > are avoiding it, and that it would be better (for qgis overall > long-term) to find and fix it. Happy to help fix it but not really sure where to start, or what I'm doing if I'm honest! The source of the image has low resolution versions so I have uploaded one of these here - 3 MB - if you want to test it yourself: http://files.shikadi.net/adam/files/qgis/georeferencer-fail.zip You don't need to georeference it in any way precisely, just pick a couple of random points and try to start the process and you'll get the error. I've tried this myself with the file in that zip and confirmed I get the same error. Cheers, Adam. _______________________________________________ QGIS-User mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
