LAStools: converting, viewing, and compressing LIDAR data in LAS format
Martin Isenburg Jonathan Shewchuk
abstract:
The program txt2las.exe converts LIDAR data from standard ASCII in various formattings to binary LAS. The corresponding las2txt.exe turns binary LAS into human-readable and easy-to-parse textual representations. The tool lasinfo.exe prints out a quick overview of the contents of a LAS file and lasmerge.exe can merge several LAS files into one and las2las.exe allows extracting only last returns, only points within a bounding box, etc. and lasthin.exe implements a simple point thinning algorithm. The little OpenGL viewer lasview.exe visualizes the contents of a LAS file. It needs the GLUT32.DLL. All these programs are command line tools and their source code (with Makefile) is available. To read gzipped inputs they need gzip.exe in the path.
We provide two simple C++ classes LASreader and LASwriter that implement reading and writing of LIDAR points from and to the binary LAS format 1.1 (as described in the May 2005 specification) that are included in the lastools.zip distribution. If you find this software useful, if you find bugs, or if you have additions or suggestions to our code, please let us know.
We also provide a simple tool laszip.exe for lossless compression and decompression of LIDAR data stored in the LAS format (versions 1.0/1.1), the binary standard format. The achieved compression is 2 to 4 times better than gzip -9. The coder is still in development and feedback is appreciated. There is also an API for reading and writing from and to our compressed format.
If you work with LAS or LIDAR you may also be interested in Visualizing LIDAR in Google Earth. There you find tools that would be called lasDEM.exe and lasTIN.exe and lasContour.exe if they were listed here. They turn lidar points into DEMs, TINSs, or Contours.
download: (updated on april 19th, 2008)
example LIDAR data (sample files) in LAS format:
related publications:
related downloads:
If you are interested in stream processing of terrain data let us know! Source code, programming APIs, and help for building your own stream processing modules is available on request.
funding: