[GRASS-user] LiDAR LAS import

[Rebecca Bennett]

sorry for the delayed reply - (windoze day yesterday)

>Hmm. Is lasinfo --help working?

Yes. wont paste the output here but it is as expected.


>liblas-config --libs
-L/usr/lib -lgeotiff -L/usr/lib -lgdal1.6.0
>liblas-config --includes
-I/usr/include/geotiff -I/usr/include/gdal

Thanks,

Rebecca



>________________________________
>From: Markus Metz <markus.metz.giswork at googlemail.com>
>To: Rebecca Bennett <rabennett at ymail.com>
>Cc: "grass-user at lists.osgeo.org" <grass-user at lists.osgeo.org>
>Sent: Wednesday, 27 July 2011, 18:01
>Subject: Re: [GRASS-user] LiDAR LAS import
>
>On Wed, Jul 27, 2011 at 3:28 PM, Rebecca Bennett <rabennett at ymail.com> wrote:
>> sure -
>>
>> checking whether to use libLAS... yes
>> checking for liblas-config... /usr/bin/liblas-config
>> configure: error: *** Unable to locate libLAS library.
>>
>> I have the packages liblas1, liblas-dev, lib-las-bin and python-liblas
>> installed through synaptic and am wondering if there is a libraty package
>> missing?
>
>Hmm. Is lasinfo --help working?
>
>What does
>liblas-config --libs
>and
>liblas-config --includes
>say?
>
>
>>
>> ________________________________
>> From: Markus Metz <markus.metz.giswork at googlemail.com>
>> To: Rebecca Bennett <rabennett at ymail.com>
>> Cc: "grass-user at lists.osgeo.org" <grass-user at lists.osgeo.org>
>> Sent: Wednesday, 27 July 2011, 13:16
>> Subject: Re: [GRASS-user] LiDAR LAS import
>>
>> Rebecca Bennett wrote:
>>> Hello,
>>> Just trying to install GRASS 7 on Ubuntu 10.04 to try out the las import
>>> functions but I'm getting error messages during the configure that it is
>>> unable to find the liblas library, however the liblas library is installed
>>> in usr/bin/lib/ so I'm a bit puzzled...
>>
>> Can you post the exact error message? Also, liblas support will only
>> be available if liblas-config exists.
>>
>> Markus M
>>
>>> Did anyone else get stuck here or am I missing something obvious?
>>> Thanks for reading,
>>> Rebecca
>>>
>>> ________________________________
>>> From: Markus Metz <markus.metz.giswork at googlemail.com>
>>> To: Hamish <hamish_b at yahoo.com>
>>> Cc: grass-user <grass-user at lists.osgeo.org>; GRASS developers list
>>> <grass-dev at lists.osgeo.org>
>>> Sent: Wednesday, 25 May 2011, 12:48
>>> Subject: Re: [GRASS-user] LiDAR LAS import
>>>
>>> On Wed, May 25, 2011 at 12:16 PM, Hamish <hamish_b at yahoo.com> wrote:
>>>> Markus Metz wrote:
>>>>> Hi all,
>>>>>
>>>>> GRASS 7 has a new module v.in.lidar for importing LiDAR LAS files
>>>>> (*.las or *.laz). The LAS file format is commonly used for storing
>>>>> LiDAR point clouds, but is unfortunately not supported by OGR.
>>>>> v.in.lidar uses the libLAS library [0] and is only compiled if the
>>>>> libLAS library is present.
>>>>>
>>>>> I chose to use the library instead of writing a custom LAS reading
>>>>> interface because the current LAS library version 1.6.1 is stable,
>>>>> supports LAS file versions 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, each of
>>>>> which can store LiDAR points in up to 5 different point formats. The
>>>>> user and the interface do not need to know the file version and point
>>>>> format of a given file, all that is conveniently handled by the libLAS
>>>>> library in the background. The library has Large File Support (LFS)
>>>>> and is well tested on different platforms, also with different
>>>>> endian-ness. This functionality is not that easy to replicate.
>>>>>
>>>>> You will need to get the libLAS library and configure GRASS 7 with
>>>>> --with-liblas in order to have the module available. Please test!
>>>>>
>>>>> Markus M
>>>>>
>>>>> [0] http://www.liblas.org
>>>>
>>>>
>>>> neat! any time trials to say how much faster it is than piping
>>>>  las2txt | v.in.ascii
>>>> ?
>>>
>>> Note that las2txt does NOT apply scale and offset to x,y,z, this would
>>> need to be done afterwards in order to obtain correct coordinates.
>>> Therefore the output of las2txt | v.in.ascii with the sample las file
>>> I used is incorrect.
>>>
>>> I discovered a bug in v.in.ascii: from a point file with | as field
>>> separator like
>>>
>>> 1|2|3||5|6
>>>
>>> only the first 3 columns will be imported because column 4 is empty
>>> which means that columns 5 and 6 are skipped.
>>>
>>> v.in.lidar is a notch faster than las2txt | v.in.ascii. And easier to
>>> use...
>>> Speed comparisons:
>>>
>>> # sample las file with 1,287,775 points
>>>
>>> # with table and topology
>>> time las2txt -i points.las --stdout --parse xyztinrcCpedRGBau
>>> --delimiter "|" | v.in.ascii in=- out=points_ascii -z x=1 y=2 z=3 --o
>>>
>>> real    6m34.430s
>>> user    4m57.530s
>>> sys    2m3.693s
>>>
>>> time v.in.lidar in=points.las out=points_las -o --o
>>>
>>> real    6m13.823s
>>> user    4m32.061s
>>> sys    2m1.068s
>>>
>>>
>>> # without table, with topology
>>> time las2txt -i points.las --stdout --parse xyz --delimiter "|" |
>>> v.in.ascii in=- out=points_ascii -zt x=1 y=2 z=3 --o
>>>
>>> real    1m53.578s
>>> user    1m47.032s
>>> sys    0m9.238s
>>>
>>> time v.in.lidar in=points.las out=points_las -ot --o
>>>
>>> real    1m44.876s
>>> user    1m34.450s
>>> sys    0m8.488s
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>>
>>
>>
>
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