LAStools now support more than 4,294,967,295 points

[Martin Isenburg]

hello,

the LAS/LAZ format is currently limited to files containing a maximum
of 2^32-1 = 4,294,967,295 points because the point counters are
internally represented with 32 bits. however, some of people that i
work with have 25 billion points or more and would like to process
them as a single unit.

LAStools now supports inputs with more than 4,294,967,295 points for
tiling, gridding, splitting, thinnig, etc ... inputs with more than
4,294,967,295 points can be specified either by merging multiple LAS
files or by converting a really large ASCII files on-the-fly. you can
simply use wildcards such as '*.las' together with the command line
flag '-merged' to specify that multiple LAS/LAZ/ASCII files are to be
treated as one.

in addition, lasmerge now has a new option '-split 500000000' that
allows you to "chop" one large on-the-fly converted ASCII file or a
merge of many LAS/LAZ files into a set of enumerated LAS or LAZ files
that each have less than 4,294,967,295 points (in this case 500
million). here are some examples for eleven 10GB input files named
"all00.las" to "all10.las" that each contain over 500 million points.

lasgrid -v -i all*.las -merged -step 20 -o dem.asc
gridding 5501554443 points onto 50395 by 30500 grid (step = 20 units)
using 'elevation lowest'

lasthin -v -i all*.las -merged -step 100 -o thinned.laz
thinning 5501554443 points onto 10079 by 6100 grid (grid_spacing =
100.00 units)

lastile -v -i all*.las -merged -tile_size 10000 -o tiles
reading 5501554443 points and tiling with size 10000 ...

las2txt -v -i all*.las -merged -parse xyz -o all.txt
processing 5501554443 points with 'xyz' ...

lasmerge -i all*.las -split 1000000000 -v -o split000.laz -nil
merging headers took 0.125 sec. there are 5501554443 points in total.
splitting file 'split000.laz' took 1932.43 sec.
splitting file 'split001.laz' took 1930.91 sec.
splitting file 'split002.laz' took 1937.83 sec.
splitting file 'split003.laz' took 1933.11 sec.
splitting file 'split004.laz' took 1929.43 sec.
splitting file 'split005.laz' took 978.39 sec.

lasinfo -i all*.las
extended LAS file has 5501554443 points, more than 32 bits can count.
reporting all LAS header entries:
file signature: 'LASF'
file source ID: 0
reserved (global_encoding):0
project ID GUID data 1-4: 0 0 0 ''
version major.minor: 1.2
system identifier: 'LAStools (c) by Martin Isenburg'
generating software: 'created by LASreaderASCII'
file creation day/year: 13/2006
header size 227
offset to point data 227
number var. length records 0
point data format 0
point data record length 20
number of point records 1206587147
number of points by return 1206587147 0 0 0 0
scale factor x y z 0.01 0.01 0.01
offset x y z 2000000 600000 0
min x y z 1930000.09 390000.00 -131.07
max x y z 2937881.73 999999.97 888.58

cheers,

martin @lastools