Convert ECW to KMZ

Understanding ECW and KMZ file formats

ECW (Enhanced Compression Wavelet) is a highly compressed raster image format commonly used for storing large aerial and satellite imagery. It is popular in the geospatial industry due to its efficient compression and fast display capabilities.

KMZ is a compressed version of the KML (Keyhole Markup Language) file format, used by Google Earth and other GIS applications to display geographic data, including images, overlays, and placemarks. KMZ files can contain images, 3D models, and other resources bundled together for easy sharing and visualization.

Why convert ECW to KMZ?

Converting ECW to KMZ allows you to visualize large georeferenced raster images in Google Earth or other compatible GIS platforms. This is useful for sharing spatial data with users who may not have access to specialized GIS software but can use Google Earth.

How to convert ECW to KMZ

To convert an ECW file to a KMZ file, you need to reproject and export the raster image into a format compatible with Google Earth. This typically involves converting the ECW to a supported raster format (like JPEG or PNG), then creating a KML overlay and packaging it as a KMZ.

Recommended software for ECW to KMZ conversion

• Global Mapper: A powerful GIS application that supports both ECW and KMZ formats. You can open your ECW file, then use File → Export → Export Web Format → Export KML/KMZ to create a KMZ overlay.
• QGIS: A free, open-source GIS tool. Load your ECW file, then use the Project → Import/Export → Export Project to KML or the Raster → Conversion → Translate (Convert format) tool to export your raster as an image, and then create a KML overlay using the Raster → Miscellaneous → Build Virtual Raster and Raster → Conversion → Polygonize tools. Finally, package the KML and image as a KMZ.
• GDAL: A command-line tool for advanced users. Use gdal_translate to convert ECW to JPEG or PNG, then gdal2tiles.py or gdal_translate -of KMLSUPEROVERLAY to create a KMZ.

Step-by-step conversion using Global Mapper

1. Open your ECW file in Global Mapper.
2. Go to File → Export → Export Web Format → Export KML/KMZ.
3. Configure the export settings, such as image format, tiling, and coordinate system.
4. Click OK to export your KMZ file.

Tips for successful conversion

• Ensure your ECW file is georeferenced correctly before conversion.
• Large ECW files may need to be downsampled or tiled for efficient use in Google Earth.
• Check the resulting KMZ in Google Earth to verify correct placement and appearance.

Conclusion

Converting ECW to KMZ enables easy sharing and visualization of geospatial imagery in Google Earth. Global Mapper is the most straightforward tool for this conversion, but QGIS and GDAL are excellent alternatives for users seeking free or open-source solutions.