W Randolph Franklin home page
... (old version)
Research/ home page Login

(in WR FranklinResearch)

Mike Gousie and I have new techniques for the classic problem of converting elevation contours to a grid. Our innovations reduce the terracing effect seen in many other methods, and produce a smoother, more realistic, result.

These techniques extend to generally fitting surfaces to points, and are used in some of our Alternate Terrain Reps.


  1. bibtexsummary:[/wrf.bib,Gousie05]
  2. bibtexsummary:[/wrf.bib,gousie98]
    Abstract: We present two new methods for approximating elevation data from contours to a grid. The first repeatedly interpolates new contour lines between the original ones. The second starts with any interpolated or approximated surface, determines its gradient lines, and does a Catmull-Rom spline interpolation along them to improve the elevations. We compare the new methods to a more classical thin-plate approximation on various data sets. The new methods appear visually smoother, with the undesirable terracing effect much reduced.
    Talk slides
    Old version of the Matlab code for the preliminary overdetermined Laplacian method.
  3. bibtexsummary:[/wrf.bib,acmgis2003]

PhD graduate

Michael B Gousie ''Contours to Digital Elevation Models: Grid-based Surface Reconstruction Methods'', 1998.

Masters graduate

John Childs ''Development of A Two-Level Iterative Computational Method for Solution of the Franklin Approximation Algorithm for the Interpolation of Large Contour Line Data Sets'', 2003.