Prototype Released for Native LAS 1.4 Extension of LASzip Lidar Compressor - 13/02/2017
Just before the kick-off of ILMF 2017 in Denver, the makers of the Lidar processing software LAStools announced that the prototype for the 'native LAS 1.4 extension' of their award-winning open source LASzip Lidar compressor is ready for testing. An update to the compressed LAZ format had become necessary due to a core change in the ASPRS LAS 1.4 specification which had introduced several new point types.
A new feature of the updated LASzip compressor is the ability to selectively decompress of only those attributes of each point that really are needed by the application that is reading the LAZ file. Minimally this will be the x and y coordinate of each point and the return counts, which are sufficient to - for example - calculate the exact extend of the survey area. Most applications will also want to access z coordinate. However, the intensities, the GPS times, the RGB or NIR colours, and the new "Extra Bytes" are often not needed. As the updated LAZ format compresses these different attributes into separate layers, their decompression can then be skipped. Therefore sometimes only 40% of a compressed LAZ file needs to be decompressed to access the coordinates of points with many attributes.
The new LASzip prototype is currently being crowd-tested. Interested parties who already have holdings of LAS 1.4 files with point types 6 to 10 may send an email to [email protected] to participate in these tests.Last updated: 22/03/2019