Convert JNX to KML

Understanding JNX and KML file formats

JNX files are raster map files used primarily by Garmin GPS devices. They store map tiles and are often used for displaying custom maps on compatible Garmin handhelds. KML (Keyhole Markup Language) files, on the other hand, are XML-based files used to display geographic data in mapping applications like Google Earth and Google Maps. KML files can contain points, lines, polygons, and image overlays, making them highly versatile for sharing and visualizing geospatial information.

Why convert JNX to KML?

Converting JNX to KML allows you to use your Garmin map data in a wider range of applications, such as Google Earth, GIS software, or web mapping platforms. This conversion is useful for sharing, editing, or visualizing your GPS data beyond Garmin devices.

How to convert JNX to KML

Direct conversion from JNX to KML is not straightforward, as JNX files are raster images while KML is a vector-based format. However, you can extract georeferenced images from JNX and then create a KML overlay. Here’s a general workflow:

1. Extract raster images from JNX: Use a tool like JNX2IMG or GMapTool to extract the map tiles or images from your JNX file.
2. Georeference the images: If the extracted images are not already georeferenced, use GIS software like QGIS to assign geographic coordinates.
3. Create a KML overlay: In QGIS, add the georeferenced image, then use Project → Import/Export → Export Map to KML to generate a KML file with the image overlay.

Recommended software for JNX to KML conversion

• JNX2IMG: Extracts images from JNX files.
• GMapTool: Can read JNX files and export map data.
• QGIS: Free and open-source GIS software for georeferencing and exporting to KML.

For most users, QGIS is the best choice for creating KML overlays from extracted JNX images, thanks to its robust georeferencing and export capabilities.

Summary

While there is no one-click solution for converting JNX to KML, using tools like JNX2IMG or GMapTool to extract images, followed by QGIS for georeferencing and KML export, provides a reliable workflow for bringing Garmin map data into KML-compatible applications.