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I've created a series of DEM files using the las2dem tool from LAStools; however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for removing these streaks?

Here's a screenshot of the issue...

PolyGeo
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MAPO
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    LAStools licensing is very reasonably priced compared to other software packages. This is by far your best bet. Alternatively, use FUSION, which is free: http://forsys.cfr.washington.edu/fusion/fusionlatest.html – Aaron Jun 29 '15 at 18:26

3 Answers3

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As mentioned by Aaron, two options are:

i) acquiring a licensed version from LAStools which won't add the streaks in the DEM from the las2dem tool.

ii) using an alternative [free] software. For example:

iii) try using blast2dem tool (free version) as suggested in LAStools' answer.

Andre Silva
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PDAL's writers.gdal supports IDW-style interpolation which may be useful depending on the situation. The PDAL workshop provides an exercise describing how to use it to create a DTM and a hillshade with gdaldem.

Howard Butler
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You can also use the blast2dem tool instead of the las2dem which has a much higher "free" limit of 6 million points per file.

At the same time use smaller tiles and also pre-filter the tiles to contain only the points you are interested in (e.g. only class 2 points, only the highest points on a 1 meter grid, only the first returns, ... ).

Make sure you use tiles with buffers to avoid edge artifacts:

Andre Silva
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LAStools
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  • blast2dem point size limit appears to be 5M points not 6M. I used the blast tool versus las2dem along with the pre filter suggestion of "keep classification" value of "2" (for ground points only) to get the point size under 5M points and it worked great. No stripes! – user88851 Dec 30 '18 at 22:36