I’m learning about making maps and have a question. I’ve been using Goggle Earth to upload different maps of different areas. It saves the custom maps in the custom maps of my Garmin Map 62 S folder as a KMZ file. CustomMaps are raster maps (bitmaps). IMG files are vector maps. CustomMaps don’t contain any data that could be converted unless you actually want to trace everything, then assign proper types to it. I would suggest using GPSBabel to convert the KMZ files to GPX format. you can then import them into GPSMapedit or use something like GPX2IMG. Do you really think so? His post seemed very clear to me that he was using Garmin’s ‘Custom Maps’ format with a .kmz file in the CustomMaps folder. There are a couple programs that will convert raster imagery to .img files, but they have limitations. You could try MOAGU and see if it works with your maps. The author is a member here and he frequently assists users with his software. Source.