[pdal] Obtaining "stats" without reading points

[Gerlek, Michael]

Would that it were so.

You *could* crawl the metadata object to find the las header, BUT it’s a bad idea: the values in the header can’t be relied on, as the generating apps often get it wrong. LAS is notorious on this one. Trust me. :-)     (trivial example: sometimes the min/max corresponds to the data *before* they did some cleaning to remove noise points……..)

Furthermore, because PDAL is a general / format-independent library, it tends to only expose as 1st class citizens the info that it “knows” is always true and will always be there for all formats.

-mpg



On Dec 3, 2014, at 10:51 AM, Kramer, Oscar <OKramer at radiantblue.com<mailto:OKramer at radiantblue.com>> wrote:

Hi,

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?

Thanks,
Oscar
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