im trying to write a google maps application. and i wanted to only highlight one city in the world ( im using the masking method explained: https://github.com/vasile/geomask) but now im bugged with the question of how to only show the boundaries of the city as displayed in google maps. can any one suggest how to extract the boundaries of the city from google maps in KML file so that i can use the same. in my project.
You cannot extract data from Google Maps.
What you could do, is to get the data from other sources. Depending on your Area of interest, the boundary might be available from your local government agency, or even OpenStreetmap.