NUMERICAL MAP DATA PROCESSING METHOD, NUMERICAL MAP DATA PROCESSING PROGRAM, AND NUMERICAL MAP DATA PROCESSING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a numerical map data processing method for expressing a landform in topographic indices composed of a plurality of elements on the basis of a numerical map so as to create a map with excellent visibility.;SOLUTION: An altitude value k at each lattice point E is read from numerical map data 50. A range constituted of a plurality of lattice points E surrounding the central lattice point is set to be a nearby range NA. Out of the altitude values k of all the lattice points E in the nearby range NA, a peak contact altitude value k_max and a valley contact altitude value k_min are read and, from the expression R=(k-k_min)/(k_max-k_min), a ratio altitude value R is calculated. Next, on the basis of the altitude value k of each lattice point E, the tilt angle of the slope of each lattice point E is calculated. Then, for every lattice point E, a topographic index T is calculated from the expression T=log(ktanR). Then, color image data are calculated from the topographic index T for every lattice point E and, by making the color image data correspond to lattice point by an operation such as pasting the color image data to each lattice point E, a topographic map is created, displayed on a display section 5 and outputted by an output section 6.;COPYRIGHT: (C)2010,JPO&INPIT