Bug report #15314

Different projection definitions for 32 and 64 bit

Added by Wouter van Esse about 7 years ago. Updated over 4 years ago.

Affected QGIS version:master Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:up/downstream
Crashes QGIS or corrupts data:No Copied to github as #:23246



I am using QGIS on different pc's and noticed a difference in the definition of EPSG:28992 when working with the raster tools in QGIS and when using GDAL through the OSGeo4W Shell. For EPSG:28992 the line that start with ' TOWGS[...' is missing when writing new files using a 32bit installed version of QGIS when reading the projection info (gdalinfo) with the 64bit installed versions. This sometimes causes problems reading and editing the files on 64bit versions. In my workflow the rasters are modified on windows and used by a different process that runs on Linux 64 bit

I have tested using several QGIS-versions (2.8.3/2.8.6/2.14.4) that also have different GDAL versions associated with them, but I find the line is always missing in 32bit versions.
I have read the projection definition using gdalinfo and python via the OSGeo4W Shell.

I have added some example-files.

Used commands in OSGeo4W Shell:
gdal_translate olf.tif new.tid -a_srs EPSG:28992

from osgeo import gdal

Hope you can help or send me to someone who can.

gdal_tests.zip (83.1 KB) Wouter van Esse, 2016-07-21 12:15 AM


#1 Updated by Andre Joost about 7 years ago

I can not reproduce your error on QGIS 2.14.4 32-bit vs 2.16.0 64-bit. The files always have the full towgs84 values.

Can you try using gdalwarp with s_srs and t_srs?

The attached files seem to be missing.

#2 Updated by Wouter van Esse about 7 years ago

I tried to attach the files again.

I have failed to mention one thing. Only when reading with an older version of QGIS the TOWGS line is missing. The latest versions do show the TOWGS line.

I'm reading (gdalinfo) using QGIS 2.8.6 that uses GDAL 1.11.3.

#3 Updated by Jürgen Fischer about 7 years ago

  • Priority changed from Normal to Low

#4 Updated by Andre Joost about 7 years ago

As far as I see, the +towgs84 values are alwas in the proj.4 string, and the WKT contains the EPSG code. So there should be little problem with the datum shift. Rasters from ESRI software never have the TOWGS84 values stored in the WKT file.

This might be an upgrade from GDAL, nothing that QGIS can do about. Using older versions of QGIS or GDAL is not recommended.

#5 Updated by Giovanni Manghi over 6 years ago

  • Easy fix? set to No
  • Regression? set to No

#6 Updated by Jürgen Fischer about 6 years ago

  • Category set to Unknown

#7 Updated by Giovanni Manghi over 4 years ago

  • Status changed from Open to Feedback

Please check if this issue is still valid on QGIS 3.4.5 or 3.6.

#8 Updated by Nyall Dawson over 4 years ago

  • Status changed from Feedback to Closed
  • Description updated (diff)
  • Resolution set to up/downstream

With QGIS 3.8 and the release of proj 6 library, any remaining projection definition related issues now should be filed with the proj project.

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