[pdal] Obtaining "stats" without reading points

[Kramer, Oscar]

Hi Andrew,

JSON would work.

Re the untrustworthy data: that's a bummer. But perhaps certain dimensions are more trustworthy than others, and the user will know which ones are good for specific datasets. In those cases, getting to the header data is still a worthwhile effort.

Oscar

________________________________
From: Andrew Bell [andrew.bell.ia at gmail.com]
Sent: Wednesday, December 03, 2014 11:47 AM
To: Kramer, Oscar
Cc: pdal at lists.osgeo.org
Subject: Re: [pdal] Obtaining "stats" without reading points

On Wed, Dec 3, 2014 at 9:51 AM, Kramer, Oscar <OKramer at radiantblue.com<mailto:OKramer at radiantblue.com>> wrote:
This is related to Michael's issue post here: https://github.com/PDAL/PDAL/issues/569. I need access to min/max bounds on quantities like intensity values, geographic bounds, etc (specifically in las files but should be generalized). I know those values are available in the las header. Yet it seems that to obtain these "stats", I need to employ a stats filter and read all the points. Is there another mechanism for quickly reading certain general properties (like bounds) that may be available from the header?

I've written the infrastructure to provide what you're asking, but I don't think I ever hooked it up to a command-line app.  I'll do this shortly.  But in the end, it doesn't matter if you can't trust the data in the header, as Michael suggests is often the case.  This really is too bad -- not much point in having the data if it's not correct.

We were talking about providing JSON output.  Would this work for you?

--
Andrew Bell
andrew.bell.ia at gmail.com<mailto:andrew.bell.ia at gmail.com>
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