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Abstract |
Airborne laser scanning technology (LiDAR) makes it easy to collect large amounts of point data that sample the elevation of the terrain beneath. The LAS format has become the de facto standard for storing and distributing the acquired points. As the sampling density of LiDAR increases so does the size of the resulting files. Typical LAS files contain tens to hundreds of millions points today, but soon billions will be commonplace.
We describe a completely lossless compression scheme for LiDAR in binary LAS format versions 1.0 to 1.3. Our encoding and decoding speeds are around one to three millions points per second and our compressed files are only 7 to 25 percent of the original file size. Compression and decompression happen on-the-fly in a streaming manner and random-access is supported with a default granularity of 50,000 points. A reference implementation unencumbered by patents or intellectual property concerns is freely available with an LGPL-license, making the proposed compression scheme suitable to become part of the LAS standard. |
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