[Liblas-devel] LAS file Coordinate Systems

[Howard Butler]

Are you by chance confusing LAStools with libLAS?

LAStools has a partial implementation of some geotiff key reading/ 
writing.  libLAS, which implements the command line utilities of  
LAStools, uses libgeotiff for geotiff key reading/writing and provides  
a much more complete implementation.

Your results will differ depending on which one (LAStools or libLAS)  
you are using.

Howard


On Jul 23, 2009, at 3:00 PM, Patel, Ronak Avinash (US SSA) wrote:

> I am using lasinfo.exe to display the fields. I downloaded lastools
> separately for Windows.
>
>
> -----Original Message-----
> From: liblas-devel-bounces at lists.osgeo.org
> [mailto:liblas-devel-bounces at lists.osgeo.org] On Behalf Of Howard  
> Butler
> Sent: Thursday, July 23, 2009 12:55 PM
> To: Liblas-devel at lists.osgeo.org
> Subject: Re: [Liblas-devel] LAS file Coordinate Systems
>
>
> On Jul 23, 2009, at 1:39 PM, Patel, Ronak Avinash (US SSA) wrote:
>
>> Howard and Mateusz,
>>
>> Thanks for the help...really appreciate it. Haven't really found many
>> people out there that know the low levels as much as you guys do.
>>
>> I was looking at the LAS 1.2 spec and it says the Georeferencing
>> information requires the GeoKeyDirectoryTag Record.
>>
>> I am able to write that tag out but I see that lasinfo always shows
>> the
>> version to be 0.0.0 regardless of what I put in those fields.
>>
>> According to the spec, the data should be arranged:
>>
>> wKeyDirectoryVersion = 1 (2 bytes)
>> wKeyRevision = 1 (2 bytes)
>> wMinorRevision = 0 (2 bytes)
>> wNumberOfKeys  = the number of sets of 4 unsigned shorts to follow
>>
>> I write out the above shorts and 0 out the rest of the data byte  
>> array
>> but lasinfo always shows 0.0.0 as the version.
>>
>> Is the spec wrong? Or is something else going on here that lasinfo  
>> and
>> libLAS are doing??
>
> Are you linking libLAS with libgeotiff when you compile?  libLAS
> completely ignores georeferencing if libgeotiff is not linked at
> compile time.
>
> Howard
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