Patent ID: 7792331

Claim:
A non-transitory computer-readable storage medium storing program code for causing a computer to perform a method of: importing a plurality of raster geographical map files, each raster file including geographical information identifying raster image data comprising color values for a plurality of pixel locations (i 1 , j 1 ), global positioning reference data for identifying pixel locations (i, j) and planar Cartesian coordinates (x, y) that correspond to one another, and a first projection that transforms geographical longitude-latitude coordinates (θ, φ) to planar Cartesian coordinates (x, y); importing a vector geographical map file, the vector file including geographical information identifying vector objects; for each of the plurality of raster files and their corresponding first projections, rendering a corresponding planar raster image comprising, for each pixel location (i 2 , j 2 ) from a plurality of pixel locations (i 2 , j 2 ): transforming planar Cartesian coordinates (x 2 , y 2 ) corresponding to the pixel location (i 2 , j 2 ), to geographical longitude-latitude coordinates (θ, φ) according to the inverse of a prescribed second projection, wherein the second projection also transforms geographical longitude-latitude coordinates (θ, φ) to planar Cartesian coordinates (x, y); re-projecting the resulting geographical longitude-latitude coordinates (θ,φ) to planar Cartesian coordinates (x 1 ,y 1 ) according to the first projection; and assigning a color value for the pixel location (i 2 , j 2 ) according to the color value for the pixel location (i 1 , j 1 ) corresponding to planar Cartesian coordinates (x 1 , y 1 ), of the raster geographical map file; rendering a planar vector image comprising color values for the plurality of pixel locations (i 2 , j 2 ), comprising projecting substantially all of the vector objects according to the prescribed second projection; and compositing the plurality of rendered planar raster images and the rendered planar vector image as layers of a composite image.