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I was given a dataset generated in MapInfo. I need to use these files in QGIS, so I imported the .TAB files and saved them as ESRI shapefiles. I then realised the original dataset uses a custom "user defined" CRS. When I change the CRS from this user defined system to WGS84 in QGIS, serious positional errors arise! The shape is also wildly altered.

I tried converting the MapInfo data to ESRI shapefiles using ogr2gui and got the same results. User_defined_CRS_from_MapInfo_causing_trouble_in_QGIS

How can I reproject the data to overcome the positional and shape errors? Is there a way of changing the original MapInfo CRS to WGS84, ensuring the shape and desired positioning will be correct in QGIS?

  • A different shape can arise due to distortion of different map projections which can be illustrated with a Tissot's indicatrix – bennos Apr 12 '16 at 8:09
  • Based on the proj4 string, it's a Brunei or Borneo CRS. The values look a bit funky. You might try using EPSG:29873 if it's supported. – mkennedy Apr 12 '16 at 17:22
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You have to change projection when saving the file to another format (TAB to Shapefile). Right-click the tab file -> go to save as, the following window will appear:

enter image description here

In the red box, select the target projection here, then save the file to shapefile.

If the output shapfile did not give you the desired results with a correct location, this means that the original custom CRS is not recognized by QGIS. In this case you may need to define a new CRS and enter the correct parameter which must conform with the proj4 format.

To do that go to Settings -> Custom CRS Click on Plus sign and define the parameters.

  • Just to add: If you misused Set Layer CRS for the task, change it back before you Save As ..., or delete the layer and re-add it to the project. – AndreJ Apr 12 '16 at 5:42

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