las2txt¶
- Author
Martin Isenburg
- Contact
- Author
Howard Butler
- Contact
Usage¶
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las2txt (libLAS 1.6.0b3 with GeoTIFF 1.3.0 GDAL 1.8dev)
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las2txt options:
-h [ --help ] produce help message
-i [ --input ] arg input LAS file.
-o [ --output ] arg output text file. Use 'stdout' if you want it written
to the standard output stream
--parse arg The '--parse txyz' flag specifies how to format each
each line of the ASCII file. For example, 'txyzia'
means that the first number of each line should be the
gpstime, the next three numbers should be the x, y, and
z coordinate, the next number should be the intensity
and the next number should be the scan angle.
The supported entries are:
x - x coordinate as a double
y - y coordinate as a double
z - z coordinate as a double
X - x coordinate as unscaled integer
Y - y coordinate as unscaled integer
Z - z coordinate as unscaled integer
a - scan angle
i - intensity
n - number of returns for given pulse
r - number of this return
c - classification number
C - classification name
u - user data
p - point source ID
e - edge of flight line
d - direction of scan flag
R - red channel of RGB color
G - green channel of RGB color
B - blue channel of RGB color
M - vertex index number
--precision arg The number of decimal places to use for x,y,z,[t]
output.
--precision 7 7 3
--precision 3 3 4 6
If you don't specify any precision, las2txt uses the
implicit values defined by the header's scale value
(and a precision of 8 is used for any time values.)
--delimiter arg The character to use for delimiting fields in the
output.
--delimiter ","
--delimiter ""
--delimiter " "
--labels Print row of header labels
--header Print header information
-v [ --verbose ] Verbose message output
--xml Output as XML -- no formatting given by --parse is
respected in this case.
--stdout Output data to stdout
Filtering options:
-e [ --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 [ --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 lasinfo at:
http://liblas.org/utilities/las2txt.html
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The ‘-parse txyz’ flag specifies how to format each each line of the ASCII file. For example, ‘txyzia’ means that the first number of each line should be the gpstime, the next three numbers should be the x, y, and z coordinate, the next number should be the intensity and the next number should be the scan angle.
Supported entries¶
a - scan angle
i - intensity,
n - number of returns for given pulse
r - number of this return
c - classification
u - user data
p - point source ID
e - edge of flight line flag
d - direction of scan flag
R - red channel of RGB color
G - green channel of RGB color
B - blue channel of RGB color
M - vertex index number
Separators¶
The ‘-sep space’ flag specifies what separator to use. The default is a space. The following list is valid for separator characters (case sensitive):
tab
comma
colon
hyphen
dot
semicolon
Header Separators¶
The ‘-header pound’ flag results in the header information being printed at the beginning of the ASCII file in form of a comment that starts with the special character ‘#’. Other possible special characters include (case sensitive):
percent
dollar
semicolon
comma
star
colon
semicolon
Examples¶
Simple conversion to text file¶
$ las2txt -i lidar.las -o lidar.txt -parse xyz
converts LAS file to ASCII and places the x, y, and z coordinate of each point at the 1st, 2nd, and 3rd entry of each line. the entries are separated by a space.
Specifying a separator¶
$ las2txt -i lidar.las -o lidar.txt -parse txyzr -sep komma
converts LAS file to ASCII and places the gps_time as the first entry, the x, y, and z coordinates at the 2nd, 3rd, and 4th entry and the number of the return as the 5th entry of each line. the entries are separated by a komma.
Altering the header separator¶
$ las2txt -i lidar.las -o lidar.txt -parse xyzia -sep semicolon -header pound
converts LAS file to ASCII and places the x, y, and z coordinate at the 1st, 2nd, and 3rd entry, the intensity at the 4th and the scan angle as the 5th entry of each line. The entries are separated by a semicolon. at the beginning of the file we print the header information as a comment starting with a ‘#’ symbol.
Altering the coordinate order¶
$ las2txt -i lidar.las -o lidar.txt -parse xyzcu -sep tab -header percent
converts LAS file to ASCII and places the x, y, and z coordinate at the 1st, 2nd, and 3rd entry, the classification at the 4th and the user data as the 5th entry of each line. the entries are separated by a semicolon. at the beginning of the file we print the header information as a comment starting with a ‘%’ symbol.