Comment 4 for bug 172106

And just as additinal information:
KDE Marble and Google Earth are able to im- and export KML/KMZ files.
DigiKam and darktable have KML/KMZ exports for images with GPS informations.

Here is an interesting blogpost about converting lang-lat to x-y:
http://blog.procontentanddesign.com/articles/single/171_Converting_latitude-longitude_into_x-y_cordinates_for_images.htm