[gdal-dev] Converting contour lines (Shape files) into DEM

Christopher Barker Chris.Barker at noaa.gov
Mon Mar 29 13:36:49 EDT 2010

Frank Warmerdam wrote:
> gdal_fillnodata attempts to do interpolation and was designed with the
> idea of filling in between contours and holes in elevation products.   It
> isn't perfect of course, but isn't the stepwise result you are expecting.

my bad -- I was making assumptions...

> The algorithm effectively involves radial searches out from each pixel
> to be interpolated, in 4 (or 8?) directions and then weighted distance
> interpolation from the hits.

Well worth giving a try, but it sounds like it's using methods for 
interpolation arbitrarily spaced data. contours are a special case, as 
there is lots of data at particular elevations, and there is a known 
relationship between these points. What this means is that a method 
designed specifically for interpolating contours may work better.

gdal_fillnodata is sure worth a try, though.


Christopher Barker, Ph.D.

Emergency Response Division
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Chris.Barker at noaa.gov

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