Provided by: liblas-bin_1.8.1-10_amd64 bug

NAME

       las2las - Advanced LAS filtering and manipulation

SYNOPSIS

       las2las [OPTIONS]

DESCRIPTION

       las2las  reads  and  writes  LiDAR  data  in the ASPRS LAS 1.0, 1.1, and 1.2 formats while
       modifying its contents.  las2las is designed for filtering and  transformation  operations
       of LAS files.

       While  lasinfo(1),  can  do a few simple operations like updating header information, more
       drastic changes, like removing points or altering values, will require  las2las.   las2las
       is  expected  to be used for modifying single files at a time, and some las2las operations
       require multiple read passes through the points.  Some examples of operations las2las  can
       be used for include:

       · clipping of points to those that lie within a certain region specified by a bounding box
         (--extent)

       · eliminating points that are the second return (--drop-return 2),

       · eliminating points that have a scan angle above some threshold (--drop-scan-angle "<5")

       · eliminating points that have an intensity below some threshold (--drop-intensity "<15")

       · extracting only first (--first-only) or last (--last-only) returns

       · changing the format from LAS 1.0 to 1.1 or vice versa

       · eliminating points of a given classification (--eliminate class 2)

       las2las started a port of Martin Isenburg's las2las utility from LASTools ⟨http://
       www.cs.unc.edu/~isenburg/lastools/⟩  to  the libLAS library.  It is much-improved from his
       version, however, and provides a number of additional capabilities.

       See also.  libLAS’ Relationship to LAStools ⟨http://www.liblas.org/
       lastools.html#lastools-liblas⟩ contains background information on the port of Isenburg and
       Shewchuck's utilities to the libLAS library.

       · Text output describing the operation(s) is only provided when the --verbose (-v)  switch
         is provided.  Errors are reported to stderr.

       · Coordinate  reprojection, including vertical datum transformation when compiled with the
         latest GDAL ⟨http://www.gdal.org⟩ .

       · Coordinate system description and alteration.

       · Variable Length Records (VLRs) are carried forward by default.

       · VLR alteration, including adding your own VLRs with files and removal of VLRs

       · File splitting based on a specified file size (--split-mb) or points (--split-pts)

       · Ability to set coordinate offsets to minimum values of the existing coordinate space.

       · Color filtering

OPTIONS

       las2las2 options:

       -h, --help
              produce help message

       --split-mb arg (=0)
              Split file into multiple files with each being this size in MB or  less.   If  this
              value is 0, no splitting is done

       --split-pts arg (=0)
              Split  file  into multiple files with each being this many points or less.  If this
              value is 0, no splitting is done

       -i arg, --input arg
              input LAS file

       -o arg, --output arg (=output.las)
              output LAS file

       -v, --verbose
              Verbose message output

       Header modification options:

       --a_srs arg
              Coordinate system to assign to input LAS file

       --a_vertcs arg
              Override vertical coordinate system information.   Use  --a_vertcs  "verticalCSType
              [citation  [verticalDatum  [verticalUnits]]]"  For  example: --a_vertcs 5703 "North
              American Vertical Datum of 1988 (NAVD88)" 5103 9001

       --offset arg
              A comma-separated or quoted, space-separated list of offsets to set on  the  output
              file: --offset 0,0,0 --offset "1234 5678 91011"

       --scale arg
              A  list of scales to set on the output file.  Scales cannot be negative, and should
              always be a negative power of 10: --scale 0.1 0.1 0.00001

       -f arg, --file-format arg
              Set the LAS format  of  the  new  file  (only  1.0-1.2  supported  at  this  time):
              --file-format 1.2 -f 1.1

       --point-format arg
              Set the LAS point format of the new file (0, 1, 2, 3): --point-format 3

       --pad-header arg
              Add extra bytes to the existing header

       --min-offset
              Set  the offset of the header to the minimums of all values in the file.  Note that
              this requires multiple read passes through the file to achieve.

       --file-creation arg
              Set the header's day/year.  Specify either as "1 2010" for the first day  of  2010,
              or as "now" to specify the current day/year

       --add-schema
              Add the liblas.org schema VLR record to the file.

       --delete-vlr arg
              Removes  VLRs with the given name and id combination.  --delete-vlr LASF_Projection
              34737

       --add-vlr arg
              Add VLRs with the given name and id combination.  --add-vlr hobu 1234  "Description
              of the VLR" "filename.ext"

       --system-identifier arg
              Set the SystemID for the file.  --system-identifier "MODIFICATION"

       --generating-software arg
              Set the SoftwareID for the file.  --generating-software "liblas.org"

       Transformation options:

       --t_srs arg
              Coordinate system to reproject output LAS file to.  Use --a_srs or verify that your
              input LAS file has a coordinate system according to lasinfo

       --point-translate arg
              An expression to translate  the  X,  Y,  Z  values  of  the  point.   For  example,
              converting  Z  units  that  are  in  meters to feet: --point-translate "x*1.0 y*1.0
              z*3.2808399"

       --color-source arg
              A string to a GDAL-openable raster data source.  Use  GDAL  VRTs  if  you  want  to
              adjust  the  data  source  or  set  its  coordinate  system,  etc.   --color-source
              "afile.tif"

       --color-source-bands arg
              A list of three bands from the --color-source to assign to the R, G, B  values  for
              the point --color-source-bands 1 2 3

       --color-source-scale arg
              A  number  used  by --color-source to scale the input R, G, B values for the point.
              For example, to scale the 8 bit color data from an input raster to 16  bit,  the  8
              bit data should be multiplied by 257.  --color-source-scale 256

       Filtering options:

       -e arg, --extent arg
              Extent  window  that  points  must  fall  within to keep.  Use a comma-separated or
              quoted, space-separated list, for example, -e minx, miny, maxx, maxy  or  -e  minx,
              miny, minz, maxx, maxy, maxz -e "minx miny minz maxx maxy maxz"

       --minx arg
              Extent must be greater than or equal to minx to be kept.  --minx 1234.0

       --miny arg
              Extent must be greater than or equal to miny to be kept.  --miny 5678.0

       --minz arg
              Extent  must  be greater than or equal to minz to be kept. If maxx and maxy are set
              but not minz *and maxz, all z values are kept.  --minz 0.0

       --maxx arg
              Extent must be less than or equal to maxx to be kept.  --maxx 1234.0

       --maxy arg
              Extent must be less than or equal to maxy to be kept.  --maxy 5678.0

       --maxz arg
              Extent must be less than or equal to maxz to be kept.  If maxx and maxy are set but
              not maxz *and minz, all z values are kept.  --maxz 10.0

       -t arg, --thin arg (=0)
              Simple  decimation-style thinning.  Thin the file by removing every t'th point from
              the file.

       --last-return-only
              Keep last returns (cannot be used with --first-return-only)

       --first-return-only
              Keep first returns (cannot be used with --last-return-only)

       --keep-returns arg
              A list of return numbers to keep in the output file: --keep-returns 1 2 3

       --drop-returns arg
              Return numbers to drop.  For example, --drop-returns 2 3 4 5

       --valid_only
              Keep only valid points

       --keep-classes arg
              A list of classifications to keep: --keep-classes 2 4 12 --keep-classes 2

       --drop-classes arg
              A  comma-separated  list  of  classifications   to   drop:   --drop-classes   1,7,8
              --drop-classes 2

       --keep-intensity arg
              Range  in  which  to keep intensity.  The following expression types are supported:
              --keep-intensity 0-100 --keep-intensity <200 --keep-intensity >400 --keep-intensity
              >=200

       --drop-intensity arg
              Range  in  which  to drop intensity.  The following expression types are supported:
              --drop-intensity <200 --drop-intensity >400 --drop-intensity >=200

       --keep-time arg
              Range in which to  keep  time.   The  following  expression  types  are  supported:
              --keep-time    413665.2336-414092.8462    --keep-time    <414094.8462   --keep-time
              >413665.2336 --keep-time >=413665.2336

       --drop-time arg
              Range in which to  drop  time.   The  following  expression  types  are  supported:
              --drop-time <413666.2336 --drop-time >413665.2336 --drop-time >=413665.2336

       --keep-scan-angle arg
              Range  in  which to keep scan angle.  The following expression types are supported:
              --keep-scan-angle 0-100 --keep-scan-angle <100 --keep-scan-angle <=100

       --drop-scan-angle arg
              Range in which to drop scan angle.  The following expression types  are  supported:
              --drop-scan-angle <30 --drop-scan-angle >100 --drop-scan-angle >=100

       --keep-color arg
              Range  in  which  to  keep  colors.   Define  colors as two 3-tuples (R,G,B-R,G,B):
              --keep-color '0,0,0-125,125,125'

       --drop-color arg
              Range in which to drop  colors.   Define  colors  as  two  3-tuples  (R,G,B-R,G,B):
              --drop-color '255,255,255-65536,65536,65536'

       For    more    information,    see    the    full    documentation    for   las2las2   at:
       ⟨http://liblas.org/utilities/las2las2.html

EXAMPLE

       Clipping with a rectangle

       $ las2las in.las --output out.las --extent "63025000 483450000 63050000 483475000"

       clips points of in.las with x<=63025000 and y<=483450000 or x>=63050000  and  y>=483475000
       and stores surviving points to out.las.

       $ las2las in.las --output out.las --extent "63025000 483450000 0 63050000 483475000 100""

       clips points of in.las with x <= 63025000 and y <= 483450000 and z <= 100 or x >= 63050000
       and y >= 483475000 and z >= 0

       note.  The quotes around the extent values are important to aid the command line  parsing.
       An  error will likely result of not quoting the values.  Alternatively, you can use commas
       to separate the --extent parameters to avoid quoting.

       Eliminating specified returns

       $ las2las --input in.las --output out.las --drop-returns 1

       eliminates all points of in.las that are designated first returns by the  value  in  their
       return_number field and stores surviving points to out.las.

       $ las2las --input in.las --output out.las --drop-returns 2 3 4 5

       eliminates all returns in the specified list.

       Limiting based on scan angle

       $ las2las --input in.las --output out.las --keep-scan-angle "<=15"

       keeps all points of in.las whose scan angle is <= 15.

       Limiting based on intensity

       $ las2las --input in.las --output out.las --drop-intensity "<=1000"

       eliminates  all points of in.las whose intensity is below 1000 and stores surviving points
       to out.las.

       Extract last returns

       $ las2las --input in.las --output out.las --last-return-only

       extracts all last return points from in.las and stores them to out.las.

       Throw out invalid data

       $ las2las --input in.las --output out.las --valid-only

       removes invalid (according to the ASPRS  LAS  file  format  specification)  points.   This
       switch  should  only  be  required  in  a few special circumstances.  Points that might be
       invalid include those with larger-than-required scan angles.

       Eliminate ground points

       $ las2las --input in.las --output out.las --drop-classes 2

       removes points with that have a classification of 2. Points with a classification of 2 are
       conventionally called ground points, but that convention may not be followed for older LAS
       1.0 files.

       Eliminate ground and unclassified points

       $ las2las --input in.las --output out.las --drop-classes 1 2

       removes points that have a classification of 1 or 2.

       Convert to 1.1

       $ las2las --input in.las --output out.las --format 1.1

       converts the in.las file to a 1.1-formatted file.  For the most part, this  conversion  is
       "in name only."

       Alter vertical datum information

       $ las2las in.las --a_vertcs 5703 "North American Vertical Datum of 1988 (NAVD88)" 5103 9001

       sets  the  vertical  datum  information  for  the file to be NAVD88 with vertical units of
       meters.

       note.  This may not be relevant depending upon the circumstances of the coordinate  system
       the  file  is  already  in.  This option only changes the *description* of the points.  It
       does not reproject them in any way.  Use a  combination  of  --a_srs  and  --t_srs  to  do
       perform reprojection of the file.

       File splitting

       $ las2las in.las --split-mb 10

       splits  the  file  into  the  required  number  of  output-n.las  files.  Other filters or
       operations may also be applied to the  operation  in  combination  with  splitting.   Each
       outputted file will have its extents and point counts properly set.

       $ las2las in.las --split-pts 100000

       splits  the file into the required number of output-n.las files with 100000 points each in
       them.  Other filters or operations may also be applied to  the  operation  in  combination
       with splitting. Each outputted file will have its extents and point counts properly set.

       note.   --split-mb  and --split-pts will not work exactly with --min-offset.  --min-offset
       will take the minimum offsets of the entire file, not  each  individual  file  that  is  a
       result of the split.

       VLR addition

       $ las2las in.las --add-vlr CUSTOM_VLR 42 "A VLR description" "myfile.ext"

       adds  a  new  VLR  with  name  CUSTOM_VLR  and  an ID of 42.  "myfile.ext" can either be a
       location to a file to read to write into the VLR, or properly escaped text  that  will  be
       inserted directly into the VLR.

       warning.   VLRs  have  a  size  limitation of 65536 bytes.  Files that are read or escaped
       arguments that are larger than 64k in size will cause an error to  be  thrown.   Automatic
       truncation will not happen.

       note.   If you attempt to add VLRs with an ID of 34735, 34736, or 34737, your VLR will not
       be added.  This is because libLAS expects to manage the GeoTIFF keys for you.  You  should
       use  the  SRS handling facilities if you need to set GeoTIFF keys instead of attempting to
       overwrite them directly.

       VLR removal

       $ las2las in.las --delete-vlr CUSTOM_VLR 42

       removes all VLRs from in.las when writing the new output.las file.

       Adding color from an image

       It is possible to use las2las to set RGB color information from an image and set it on the
       points.   This requires a rewrite of the file and in some cases will require changing both
       the format and point-format of the file.  The following example takes the input.las  file,
       sets  its format to 1.2, and sets the point format to 3 so it can store color information.
       It also re-orders the color bands to have the 3rd band in the image be red,  1st  band  be
       green, and second band be blue.  Additionally, the color values are then multiplied by the
       --color-source-scale factor or 256 to rescale the 8 bit image data to 16 bit color data.

       las2las -i input.las \
               --color-source image.img \
               -o output.las \
               --file-format 1.2 \
               --point-format 3 \
               --color-source-scale 256 \
               --color-source-bands 3 1 2

       note.  If the coordinate system of image.img is not  the  same  as  the  input  coordinate
       system  of  the  LAS  file,  you  should use GDAL VRTs to cause the image to be warped and
       reprojected as part of the read process.  See GDAL Virtual Format Tutorial ⟨http://
       www.gdal.org/gdal_vrttut.html⟩ for more detail.

       warning.  GDAL ⟨http://www.gdal.org⟩ support must be enabled for this to work.

                                         16 February 2019                              las2las(1)