I have a .kmz file that I can't load properly into QGIS. I already rename the file as .zip and look into the files inside. I found the .kml text file and an other folder with a .png image (the one that I would like to open in QGIS as raster). When I open the .png directly in QGIS, the values doesn't make too much sense and I loose the geo-reference coordinates. Any advice on it?
KMZ files are directly readable from qgis. KMZ file is a collection of a kml and its supporting pictures. the pictures itself are not georeferenced and directly opening them will usually open then in wgs84 which won't make sense as pictures will be stretched in some direction. The KMZ is designed to work with Google Earth and the same functions are missing in qgis. The png can be viewed by configuring the display property of the layer. for that. right click the layer -> properties -> display -> HTML. Choose the field containing the link to the png. then select map tips tool from the toolbar and hover over the point. the field containing png will be displayed.
KMZ files containing a georeferenced raster can be opened with global mapper 15.2. The images will load in the correct locations if its projection is set at geographical wgs84 on global mapper 15.2. Global mapper will be able to export any image type so you could load raster into QGIS