1. A method for generating a customized composite map image, said method to be implemented by an electronic apparatus that has a map database established therein and comprising the steps of: a) receiving a user-specified input image of an area of interest; b) obtaining from the map database a reference map that encompasses the area of interest; c) selecting a set of feature points in the user-specified input image and a set of map points in the reference map that correspond in geographical features to the feature points; d) automatically transforming the user-specified input image according to positional differences between said feature points and the corresponding map points so as to obtain a to-be-registered image having adjusted feature points corresponding in position to the map points; automatically overlaying the to-be-registered image onto the reference map in a manner that the adjusted feature points coincide with the corresponding map points to thereby obtain a customized composite map image; and f) outputting the customized composite map image.