Bug report #20017

Raster - Miscellaneous - Merge ECW images

Added by ZHI JUN ZHU almost 2 years ago. Updated almost 2 years ago.

Affected QGIS version:3.2.1 Regression?:No
Operating System:Windows 10 Easy fix?:No
Pull Request or Patch supplied:No Resolution:invalid
Crashes QGIS or corrupts data:No Copied to github as #:27839


QGIS version 3.2.1-Bonn

I have many ECW image tiles, and I want to combine them into one image (mosaic).
So when I use the Raster - Misscellaneous - Merge - Parameters - Inpurt layers - select all ECW images (EPSG:26917 - NAD83 /UTM 17N)

Grab pseudocolor table from first layer: default
Place each input file into a separate band: default
Output data type: Float32
GDAL/OGR console call:
gdal_merge.bat -ot Float32 -of ECW -o C:/4_QGis/041P05K01/041p05.ecw --optfile C:/Users/zjzhu/AppData/Local/Temp/processing_8b97f0e259554203b97eecdfde25cd78\mergeInputFiles.txt

When I run in background, I got the following messages:

GDAL command output:
Format driver ECW does not support creation and piecewise writing.

Please select a format that does, such as GTiff (the default) or HFA (Erdas Imagine).

Execution completed in 0.73 seconds
Results: {'OUTPUT': <QgsProcessingOutputLayerDefinition {'sink':C:/4_QGis/041P05K01/041p05.ecw, 'createOptions': {'fileEncoding': 'System'}}>}

Loading resulting layers
The following layers were not correctly generated.<ul><li>C:/4_QGis/041P05K01/041p05.ecw</li></ul>You can check the 'Log Messages Panel' in QGIS main window to find more information about the execution of the algorithm.

Could I merge many ECW images into one ECW image ?

If yes, could you please give me some hints .



Output data

041P05K01.ecw (4.63 MB) ZHI JUN ZHU, 2018-10-04 07:03 PM


#1 Updated by Giovanni Manghi almost 2 years ago

  • Resolution set to invalid
  • Status changed from Open to Closed

No, you can't create ECW files. The ECW library/driver that is shipped with the OSGeo4W installer is read only. As far as I know the proprietary library/driver that allows to create ECW files is not freely available (in fact is very expensive).

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