Accompany the development of technology, more and more professional information is used. The appearance of Google
Earth (GE) made it possible for people to research on GIS technology. In this article, we introduced a method of how to
draw maps using the roads extraction from images in GE.
Following steps are illustrated: first, identify edges of roads using improved multiple-weighted algorithm; second, the
initial image of roads is achieved using double-thresholds algorithm; third, compare the edges information of initial
images with the image after processed by step one, and the last step , remove noises in the images using mathematical
At last, experiments are processed to improves that road information can be achieved precisely using the algorithm
introduced in the article which could be used in the projects such as land survey, map plotting etc.