I have a PNG image file.I want to convert it to GeoTiff. I installed QGIS software but i can not use it and i dont know how to Georeference the image. Please help me. is there any online software ?
This is a pretty good tutorial with step by step instructions on how to georeference an image in the GUI.
http://www.qgistutorials.com/en/docs/georeferencing_basics.html