Implementation and performance optimization of a parallel contour line generation algorithm

This paper introduces a parallel contour line interpolation algorithm from Digital Elevation Model (DEM). Contour generation from DEM is the basic task of the computer-aided mapping and one of the most important applications of DEM. With the increasing of DEM resolution, the Digital Terrain Analysis (DTA) has become one of the computing-intensive tasks in GIS. Many studies have been done on the implementation of parallel DTA algorithms based on different parallel hardware and software. In this paper, we use the open source GIS toolkit to implement a parallel contour generation algorithm. The Message Passing Interface (MPI) standard is used for the parallel algorithm programming. A slackly LAN (Local Area Network)-connected windows cluster is setup to implement and test the parallel contour line generation algorithm. The performance optimization method for the parallel algorithm is specifically discussed, including data redundancy method, group communication, packaging collection of results, and memory optimization method for results merging. The experimental results show the capacity and potential to implement the parallel GIS algorithms based on open source GIS toolkit in the LAN-connected PC environment.