Geoscience Reference
In-Depth Information
More information is provided in the PDAL tutorial.
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Also interesting for users with
a background in Python programming is
filters.programmable
.
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You can
write a piece of code in Python and use that as a filter. Reading and writing the actual
point data is taken care of by PDAL behind the scenes, so you can just concentrate
on the function to be applied to each point.
15.3.3 LAStools
A popular and one of the most complete suite of command line tools to process
LiDAR data is LAStools,
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developed by Martin Isenburg.
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Some of the utilities
are free and open source.
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More advanced utilities are closed source, but free for
scientific and educational use. Restrictions on the data size can also apply. Only the
open source utilities are shortly presented here.
lasinfo
Provides information and performs basic checking on LAS file, e.g. header and
summary of points. You can also edit and repair inconsistencies in the header file.
las2las
Transforms point cloud data in LAS, LAZ and ASCII format and implements
a variety of operations for projection and filtering transform, project, thin,
or otherwise modify its contents.
las2txt
Converts from binary LAS/LAZ 1.0 - 1.4 to an ASCII text format.
lasdiff
Compares the two LIDAR point clouds.
lasindex
Creates spatial indexing by writing a .lax file that can be used to speed up spatial
queries of subsequent LAStools utilities.
lasmerge
Merges multiple point cloud data files into a single file.
lasprecision
Computes statistics to check the precision claimed in header.
laszip
Compresses and uncompresses point cloud data to and from the lossless LAZ
format.
In a first example, we show how we can merge a number of LAZ files. The result
is a single LAZ file that contains more than 33 million points.
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