Hi it seems that it has to do something with no-data areas. gdal_contour tries to calculate all the contours from approx. 450m up to my no-data value -3.4...e+38.
I use no gdal_fillnodata.py to fill the no data areas. So I still think there is a slighly different behaviour of gdal since my last calculations with the same commands and data with Ubuntu 10.04. best regards Stefan On Thu, Apr 7, 2016 at 12:58 PM, Even Rouault <[email protected]> wrote: > Stefan, > > > I have problems creating contours with gdal_contour and some tiff files. > > The following command > > > > gdal_contour -i 1.0 6800_2480.tif out.shp > > > > ends with "0Killed" after eating all memory and all swap. It happens with > > gdal 1.11 and gdal-master. It did work on a Ubuntu 10.04 machine (as far > as > > I remember). Now I'm on Ubuntu 14.04. > > Comparing the source code, the algorithm hasn't fundamentaly changed, at > least > since GDAL 1.5. I can reproduce your issue with latest trunk or 1.5.X. > It is related to the fact that your source dataset has floating point > values. > An easy workaround is to translate your raster into a Int16 one and contour > it. I've just tried it and it works. > Or you could possibly round values to 0.5 precision with gdal_calc.py for > perhaps a smoother result. But basically the contour alg seems to require a > lot of memory if every pixel is different from its neighbour (might be an > approximation of what happens as the algorithm is non trivial and I didn't > study it in detail). > It might be worth opening a ticket on that. > > Even > > > > > Tiff file can be found here: > > http://maps.zh.ch/download/hoehen/2014/dtm/tif/6800_2480.tif > > > > Any ideas? > > > > regards > > Stefan > > -- > Spatialys - Geospatial professional services > http://www.spatialys.com >
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