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?
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
ii) using an alternative [free] software. For example:
Fusion (running from QGIS):
iii) try using
blast2dem tool (free version) as suggested in LAStools' answer.
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: