Abstract:

The isoline extracted from DEM is one of the basic functions of computer mapping and geographic information system. This paper proposes an isoline extraction method based on interval tree from DEM. This paper references the algorithm of inserting elements in balance binary sort tree to create interval tree’s nodes; when searching the grids the contour line passed, it just sorts those grids which are belonged to the nodes the search path passed, avoids sort all grids in the interval tree, and reduces the search time. Experimental results show that the algorithm has an advantage in time than the older algorithm.

Key words: isoline, DEM, AVL tree, interval tree