Bug report #10480

Georeferencer truncates coordinates to 2 decimals

Added by ujaval gandhi over 9 years ago. Updated over 8 years ago.

Category:C++ plugins/Georeferencer
Affected QGIS version:2.6.0 Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:No Copied to github as #:18892


When entering target coordinates in Georeferencer, the GCP table shows only 2 decimal values. I believe the full value is stored internally, but while transforming, the Georeferencer uses the truncated value. This is especially problematic if the GCP points are close by and truncating the coordinates to 2 decimal shifts the GCPs to a completely wrong location.

This was reported in the user list in 2011 and the issue still persists. http://lists.osgeo.org/pipermail/qgis-user/2011-December/014732.html

Associated revisions

Revision cecae9f1
Added by Nyall Dawson over 8 years ago

[georef] Fix coordinates truncated to 2 decimal places in table

Now, coordinates are shown in table to 4 decimal places, and a
tooltip will show the full precision of coordinates. Editing
coordinates also shows the full precision. (fix #10480)


#1 Updated by Jürgen Fischer over 9 years ago

  • Category changed from C++ Plugins to C++ plugins/Georeferencer

#2 Updated by Miroslav Umlauf over 9 years ago

Still happens in 2.6. I would say it is pretty high issue. For system in meters, precision to millimeters are sure fine for majority. But when using WGS 84 or any degrees, this is significant error and gives the user wrong result without any warning.

#3 Updated by Giovanni Manghi over 9 years ago

  • Affected QGIS version changed from 2.2.0 to 2.6.0

#4 Updated by Miroslav Umlauf over 9 years ago

Sorry, I did few more tests and this issue doesn't affect precision as far as the values cropped to two decimals were not updated/re-saved. Internally it keeps original values, including saving to GCP - points - file).

#5 Updated by Nyall Dawson over 8 years ago

  • Status changed from Open to Closed

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