1. An image editing system for transmission network supervision comprising: means for creating station data as a data source for graphically displaying a plurality of stations within a specific area; memory means for storing said station data; means for creating area data as a data source for graphically displaying a map of said specific area; means for creating, on the basis of said station data and said area data, map data for graphically displaying an area map including an image map of said specific area reduced to a desired scale, said plurality of stations superimposed on said image map and transmission routes connecting said plurality of stations; map memory means for storing said map data; and display means for graphically displaying said area map based on said map data; wherein said area data creating means creates said area data by first designating two reference points on a map of said specific area; reading said map containing said two reference points through an image scanner attached to said system for conversion to image data; displaying said image map in accordance with said image data on said display means arranged to appear within a window established on said display means; and plotting said two reference points and an outer frame of said image map to obtain coordinate values of said image map; wherein said map creating means comprises: means for obtaining an x direction scale value of said image map by dividing an absolute difference between x coordinate values of two display reference points on said image map by an absolute difference between latitude values of said two reference points on the map of said specific area; means for obtaining a y direction scale value of said image map by dividing the absolute difference between y coordinate values of said two display reference points by an absolute difference between longitude values of said two reference points; means for obtaining an x coordinate value of a window reference point for providing screen display reference of said window by first dividing the x coordinate value of one of said two display reference points by said x direction scale value, and by subtracting a resulting quotient from a latitude value of one of said two reference points; means for obtaining a y coordinate value of said window reference point by first dividing the y coordinate value of said one of two display reference points by said y direction scale value, and by subtracting a resulting quotient from a longitude value of said one of two display reference points; means for obtaining an x coordinate value of station display coordinates for displaying each of said plurality of stations on said image map displayed in said window, said x coordinate value being obtained by first subtracting the x coordinate value of said window reference point from an actual latitude value of each of said plurality of stations, and by multiplying a resulting difference by said x direction scale value; and means for obtaining a y coordinate value of station display coordinates for displaying each of said plurality of stations on said image map displayed in said window, said y coordinate value being obtained by first subtracting the y coordinate value of said window reference point from an actual latitude value of each of said plurality of stations, and by multiplying a resulting difference by said x direction scale value.