[Liblas-devel] Clipping

[Mateusz Loskot]

James,

Good point. Thanks for this insight.

-- Mateusz

Giglierano, James [DNR] wrote:
> Actually, we have seen regular cases of sunlight reflecting off water
> surfaces to the lidar sensor.  Since the sunlight is always on, it gives
> a false elevation of the airplane's height.  These are usually filtered
> out for the bare earth classification by the vendor, but they still
> appear in the first return data, maybe others.  Unless you are aware
> that this happens, it can be disconcerting when it first appears.  A
> height filter might be useful, or something to catch and remove outliers
> such as this.
> 
> -----Original Message-----
> From: liblas-devel-bounces at mail.hobu.net
> [mailto:liblas-devel-bounces at mail.hobu.net] On Behalf Of Mateusz Loskot
> Sent: Wednesday, April 09, 2008 11:24 AM
> To: Liblas-devel at mail.hobu.net
> Subject: Re: [Liblas-devel] Clipping
> 
> Howard Butler wrote:
>> On Apr 9, 2008, at 10:32 AM, Mateusz Loskot wrote:
>>> Hi,
>>>
>>> Do we have a tool that can clip LAS file to given extent of XYZ
> pairs?
>>> I imagine to have something like:
>>>
>>> las2las --min X1 Y1 Z1 --max X2 Y2 Z2 --in file.las --out clipped.las
>> Yep, but it only clips on x and y, not z.  I'm not sure you would want
> 
>> to clip z's out, but that could be easily added.
>>
>> http://liblas.org/browser/trunk/apps/las2las.c#L55
>>
>> las2las -i file.las --clip X1 Y1 X2 Y2 --out clipped.las
> 
> Hobu,
> 
> That's exactlu what I was looking for. You are right, clipping by Z 
> value is usually not very useful.
> 
> Cheers


-- 
Mateusz Loskot
http://mateusz.loskot.net