LASzip

LASzip is our free, open-source product to quickly turn bulky LAS files into compact LAZ files without information loss. Terabytes of LAZ data are now available for free download from various agencies making LASzip, winner of the 2012 Geospatial World Forum Technology Innovation Award in LiDAR Processing and runner-up for the innovative product at INTERGEO 2012, the de-facto standard for LiDAR compression.

LASzip squeezes the 5.3 Terabytes of LAS files that the National Land Survey of Finland serves on its public servers as part of an “open data” campaign into only 0.8 Terabytes of LAZ files.

Other success stories are OpenTopography which has been serving LAZ for two years, and the comprehensive open LiDAR archive of the Department for Natural Resources of Minnesota, which are exclusively provided in the LAZ format.

LASzip is a compression library developed by rapidlasso founder Martin Isenburg for compressing ASPRS LAS format data in LAStools. It has been provided as an LGPL-licensed stand-alone software library to allow other software that handles LAS data to read and write LASzip-compressed data. The BSD-licensed libLAS and our LASlib can use LASzip to read and write compressed data.

LASzip is entirely lossless. It compresses bulky LAS files into compact LAZ files that are only 7-20 percent of the original size, accurately preserving every single bit. For example, compressing and decompressing the LAS file lidar.las with laszip.exe as shown below, results in lidar_copy.las that are bit-identical to lidar.las. However, the small size of lidar.laz makes it much easier to store, copy, transmit, or archive large amounts of LIDAR.

LASzip compression can be much smaller and faster than generic compressors like bz2, gzip, and rar because it knows what the different bytes in a LAS file represent. Another advantage of LASzip is that it allows you to treat compressed LAZ files like standard LAS files. You can load them directly from the compressed form into your application without first decompressing them onto a disk. The availability of the LASzip DLL and two APIs, libLAS and LASlib, with LASzip capability, makes it easy to add native LAZ support to your software package.

Our free open-source LiDAR compressor LASzip has become the de-facto standard for compressed point clouds in the LiDAR industry.

laszip -i lidar.las -o lidar.laz
laszip -i lidar.laz -o lidar_copy.las

  • LASzip is included in our full download package and also available as sourcecode to be compiled in Windows, Linux or MacOS environments.
  • Find the specification of the LASzip format in this PDF.
This (may incomplete) list shows software and vendors which support LAZ format:
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