How to add .ecw reading capability to QGIS3 on MacOS

Hopefully this provides a easy to read guide on how to add .ecw reading capability to QGIS3 on MacOS.

There're 5 sections:

1. Determine your GDAL Version
2. Download the required plugin and SDK
3. Install the ERDAS ECW/JPEG2000 SDK
4. Copy over the required files to GDAL
5. Install the ECW Plugin

Assumptions:

• You can use Homebrew - If not install it from here

• You have MacOS

• You have installed QGIS3 and it's depencies via Homebrew, if not run:

  brew tap osgeo/osgeo4mac
  brew install qgis3
  

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1. Determine you GDAL Version

The ECW plugin you'll install will depend on the version of GDAL that your QGIS3 was built and is running against.

• You can find out what version you're using by loading up QGIS3 and going to the menu options:

  QGIS 3 -> About QGIS 3
  

• You'll be greeted by something like this:

• You'll notice that I'm going to target GDAL 2.3.2 (Really 2.3)

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2. Download the required plugin and SDK

To add .ecw support you'll need the ECW plugin and the ERDAS ECW/JPEG2000 SDK for your version of GDAL.

The download links can be found here

You will find a variety of versions but I'll concentrate on 2.3 (They should all be pretty similar)

For GDAL 2.3:

• ECW Plugin v2.3.2-1 Download Here
• ERDAS ECW/JPEG2000 SDK 5.4 Download Here (You'll need to give some contact details to get the download button)

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3. Install the ERDAS ECW/JPEG2000 SDK

• Open the SDK .dmg and open the .pkg file - I find right clicking and opening prevents any security warnings
• Follow the on-screen installation instructions, making sure you select Desktop Read-Only Redistributable on the License Selection page
• You shouldn't need to do anything else other than click through the install

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4. Copy over the required files to GDAL

• Open your terminal of choice and run:
  • cd /Hexagon/ERDASEcwJpeg2000SDK5.4.0/Desktop_Read-Only/lib/libc++/dynamic
  • sudo mkdir /Library/Application\ Support/GDAL/2.3/Libraries
  • sudo cp libNCSEcw.dylib /Library/Application\ Support/GDAL/2.3/Libraries/
  • sudo cp -R ../../../etc /Library/Application\ Support/GDAL/2.3/
  • tree /Library/Application\ Support/GDAL/2.3/ you should get a structure similar to:

    /Library/Application\ Support/GDAL/2.3/
    ├── Libraries
    │   └── libNCSEcw.dylib
    └── etc
    

• If you want to clear up space, you can now run: sudo rm -rf /Hexagon/

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5. Install the ECW Plugin

• Open the ECW Plugin .dmg, if you've succesfully put the SDK you should get no warning messages or errors
• Follow the installation instructions without changing any of the defaults
• Once installed, run tree /Library/Application\ Support/GDAL/2.3/ and you should get a structure with the plugin now:

  /Library/Application\ Support/GDAL/2.3/
  ├── Libraries
  │   └── libNCSEcw.dylib
  ├── PlugIns
  │   └── gdal_ECW_JP2ECW.dylib
  └── etc
  

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5.1 Fingers crossed...

Hopefully, having gotten up to this point you've not had any errors. I restarted my Mac, but it may not be necessary (I would anyway).

Open up QGIS3 and with any luck when you go to Layer -> Add Layer -> Add Raster Layer... and navigate to your .ecw file, it should load without issue!

This took me a few days to try and find a working solution that also used Homebrew for the most part. Please do give me a shout if this doesn't work for you or you have a better way to go about this.

It's easiest to tweet me @Ciaran_Evans

:)