System and method for georeferencing digital raster maps using a georeferencing function

A computer readable medium containing instructions executable by a computer to perform a method for georeferencing a raster map, the method comprising:

• displaying a first map in one area of a display, the first map being a digital raster map having a plurality of pixel locations;
• displaying a second map in a second area of the display, the second map being a georeferenced map having associated geographic coordinates and displaying at least a portion of an identical geographic region displayed in the raster map;
• receiving a first point on the first map and a corresponding first point on the second map, wherein the first point on the first map and the corresponding first point on the second map represent identical locations;
• receiving a second point on the first map and a corresponding second point on the second map, wherein the second point on the first map and the corresponding second point on the second map represent identical locations;
• receiving pixel coordinates for the first point on the first map and the second point on the first map;
• receiving geographic coordinates for the first point on the second map and the second point on the second map;
• and
• automatically computing a georeferencing function that converts between the pixel coordinates of the first map and the geographic coordinates of the second map, wherein the georeferencing function is based on the first and the second points received on the first map and the corresponding first and second points received on the second map, and assigns corresponding geographic coordinates to any one of the plurality of pixel locations.

A method of georeferencing a raster map, comprising:

• displaying a first map in one area of a display, the first map being a digital raster map having a plurality of pixel locations;
• displaying a second map in a second area of the display, the second map being a georeferenced map having associated geographic coordinates and displaying at least a portion of an identical geographic region displayed in the raster map;
• receiving two or more point-pairs, each point-pair consisting of a point from the first map and a corresponding point from the second map, wherein the point-pairs are chosen such that corresponding points of each point-pair refer to the same geographic location;
• and
• automatically computing a georeferencing function for the first map that expresses a mathematical relationship based on the two or more point-pairs and converts between pixel coordinates of an arbitrary point on the first map and corresponding geographic coordinates on the second map.

A data processing system for georeferencing a raster map, the data processing system comprising:

• a display;
• and
• a processor in communication with the display, wherein the processor executes instructions to:
• display a first map in one area of the display, the first map being a digital raster map having a plurality of pixel locations;
• display a second map in a second area of the display, the second map being a georeferenced map having associated geographic coordinates and displaying at least a portion of an identical geographic region displayed in the raster map;
• receive a first point on the first map and a corresponding first point on the second map, wherein the first point on the first map and the corresponding first point on the second map represent identical locations;
• receive a second point on the first map and a corresponding second point on the second map, wherein the second point on the first map and the corresponding second point on the second map represent identical locations;
• receive pixel coordinates for the first point on the first map and the second point on the first map;
• receive geographic coordinates for the first point on the second map and the second point on the second map;
• and
• automatically compute a georeferencing function that converts between the pixel coordinates of the first map and the geographic coordinates of the second map, wherein the georeferencing function is based on the first and the second points received on the first map and the corresponding first and second points received on the second map, and assigns corresponding geographic coordinates to any one of the plurality of pixel locations.