Convert IMG to KMZ

Understanding IMG and KMZ file formats

IMG files are raster image files, commonly used for storing graphics, satellite imagery, or scanned maps. They can be in various formats, such as ERDAS IMG (for geospatial data) or simple bitmap images. KMZ files are compressed Keyhole Markup Language (KML) files used by Google Earth and other GIS applications to display geographic data, including images, placemarks, and overlays, in a zipped format.

Why convert IMG to KMZ?

Converting an IMG file to KMZ allows you to overlay raster images (such as maps or satellite photos) onto geographic coordinates in Google Earth or similar GIS tools. This is useful for visualizing spatial data, sharing georeferenced imagery, or integrating custom maps into interactive platforms.

How to convert IMG to KMZ

To convert an IMG file to a KMZ file, you need to georeference the image and package it with a KML file that defines its placement on the globe. This process typically involves:

1. Georeferencing the IMG file (if not already georeferenced).
2. Creating a KML file that references the image as a ground overlay.
3. Compressing the KML and image into a KMZ archive.

Recommended software for IMG to KMZ conversion

QGIS (Quantum GIS) is a powerful, free, and open-source GIS application that can handle this conversion. Here’s how to do it:

1. Open QGIS and load your IMG file using Layer → Add Layer → Add Raster Layer.
2. If your image is not georeferenced, use the Raster → Georeferencer tool to assign coordinates.
3. Once georeferenced, right-click the layer and select Export → Save As....
4. Choose KML as the format and configure the export settings.
5. QGIS will generate a KML file and the referenced image. To create a KMZ, compress both files into a ZIP archive and rename the extension to .kmz.

Alternatively, Global Mapper and Google Earth Pro (for simple overlays) can also perform this conversion, but QGIS is the most versatile and accessible option.

Key considerations

• Ensure your IMG file is georeferenced for accurate placement in Google Earth.
• Large images may need to be tiled or resized for optimal performance in KMZ format.
• Check the overlay in Google Earth to verify correct alignment and appearance.