1. In a graphic computer system including a display and a plurality of geographic information systems (GIS), each of said GIS containing a plurality of data layers, each data layer comprised of georeferenced data, a method for transferring georegistering data between said plurality of GIS while preserving georeferencing and maximizing accuracy, said method comprising the steps of: a. selecting a geographic area, said area's boundary comprised of a plurality of line segments, each of said line segment being adjacent to two other of said line segments, and each line segment having two end points, each of said end point being shared with one of said adjacent line segments. Each of said geographic area end points having a coordinate pair, said coordinate pair identifying the geographic location of said end point; b. creating a template, comprising a two-dimensional polygon whose boundary is comprised of a plurality of line segments, each of said line segment being adjacent to two other of said line segments, and each line segment having two end points, each of said end point being shared with one of said adjacent line segments, said template being congruent in shape and area to said geographic area and each of said template end points being associated with one of said geographic area end points; c. determining for each of said template end points, the coordinate pair of said associated geographic area end point; d. using a first GIS to display said template on said display screen, each interior point of said template on said display being of a first data type and each exterior point of said template being of a second data type; e. creating from said template display a template file, said template file comprised of a plurality of bits, each of said bits identified with a specific point on said screen; f. creating a transform function, said transform function consisting of identifying in said template file all bits which are of said second data type and recording the location of such bits in said file; g. using said first GIS to displaying a portion of a first data layer from GIS1 on said display screen as a first map, said portion comprised of data georeferenced to said selected geographic area; h. creating from said displayed first map a first file, said first file comprised of a plurality of bits, each of said bits identified with a specific point on said screen; i. applying said transform function to said first file to create a first transformed file, said application comprised of identifying in said first file all bit positions corresponding to positions with 0 bits in said template file and deleting said identified bits; j. converting said first transformed file to the input format of a second GIS; k. using said first GIS to displaying a portion of a second data layer from said GIS1 on said display screen as a second map, said portion comprised of data georeferenced to said selected geographic area; l. creating from said displayed second map a second file, said second file comprised of a plurality of bits, each of said bits identified with a specific point on said screen; m. applying said transform function to said second file to create a second transformed file, said application comprised of identifying in said second file all bit positions corresponding to positions with 0 bits in said template file and deleting said identified bits; and n. converting said second transformed file to the input format of said second GIS.