Can't load large ECW file.


As mentioned on Gitter a large ECW file was send to me which opens fine in QGIS but MapWinGIS (nor MW5) is able to open it. Loading takes forever.

GdalInfo according to QGis:




Paul Meems
November 19, 2017, 12:26 PM

I can confirm this fix. I also removed the workaround in MW5

Jerry Faust
November 18, 2017, 8:53 PM

This has now also been resolved in the MapWinGIS FileManager class, which will no longer hang when loading a large ECW file.

Paul Meems
August 14, 2017, 8:57 PM

In D:\dev\MapWindow-v5\src\MW5.Api\Static\GeoSource.cs I changed the Open method and added

Before calling

Meaning when a ecw file is loaded open it as a BitmapSource which is in fact:

Now I don't have any problems loading the large ECW-file, nor zooming and panning.

I still think we also need to solve this in the fileManager of MapWinGIS.

Paul Meems
August 7, 2017, 8:38 PM

Thanks to the help of Tamas from GisInternals we're now using the ECW SDK 5.3 driver.
But the file can still not be loaded.

When I open the ECW-file with this piece of code:

or this piece of code:

The application hangs.

But with this piece of code I have no problem at all and the image is shown as expected and as fast as expected:

Paul Meems
July 25, 2017, 7:01 AM

When I do a GdalInfo from within MapWinGIS I get this GDALInfo:

What stands out is the use of a different driver. I'll need a closer look why we use the old version of the ECW driver.



Jerry Faust


Paul Meems


Fix versions

Affects versions