[pdal] Ferry filter not working in LAZ file

[Andrew Bell]

Hi Eric,

How do you know that the DTM field is not getting created? You'll have to
change the writer to put this field in LAS extra bytes if you want it to be
part of your output. See the option 'extra_dims' at
https://www.pdal.io/stages/writers.las.html for more info.

On Fri, Apr 13, 2018, 12:05 AM Eric Robeck <erobeck at gmail.com> wrote:

> Hello,
>
> I have written a PDAL pipeline to perform the following steps:
>
> 1.) Ferry the existing Classification to the UserData field for storage
> (this is more efficient than creating a new field)
> 2.) Use the ferry filter to create a new DTM field
> 3.) Use the colorize filter to extract the elevation value from a
> single-band TIF (a DTM made from the original ground points)
> 4.) Run SMRF to reclassify the ground points
>
> I cannot get the ferry filter to work at all. It won't transfer values
> between existing columns or create new columns, despite using the same
> syntax described on PDAL.io. I have tried various ways to get around this
> issue. Changing the order of filters.ferry in the pipeline didn't make a
> difference. I saw that the online examples worked on uncompressed LAS
> files, so I converted the input files from LAZ to LAS but there was no
> change. The pipeline completes without errors, but info --stats and info
> --schema show that the ferried fields were not created or updated.
>
> The colorize filter works fine, as long as I use an existing field. For
> example, "dimensions":"Red:1:1000.0" works by mapping the elevation values
> to the Red field and multiplying by 1000 to preserve millimeter precision
> in an integer field. However, "dimensions":"DTM:1:1000.0" does not, because
> the ferry filter doesn't create the DTM field. The SMRF filter also works
> well, but without the ability to ferry values I lose the original
> classifications.
>
> I am using PDAL 1.6.0 on Windows within OSGeo4W. It was installed this
> month. My pipeline is copied below.
>
> Any help would be greatly appreciated.
>
> Thanks,
> Eric
>
>
> {
>   "pipeline":
>   [
>     "C:/data/forest_park/filtered/forest_park_orig.laz",
>     {
>       "type":"filters.ferry",
>       "dimensions":"Classification=>UserData, =>DTM"
>     },
>     {
>       "type":"filters.colorization",
>       "dimensions":"DTM:1:1000.0",
>       "raster":"C:/data/forest_park/dtm/w001001.adf"
>     },
>     {
>       "type":"filters.smrf",
>       "cell":1.00,
>       "cut":0,
>       "scalar":1.25,
>       "slope":0.00,
>       "threshold":0.50,
>       "window":10
>     },
>     {
>       "type":"writers.las",
>       "tag":"writerslas",
>       "compression":"true",
>       "scale_x":"0.01",
>       "scale_y":"0.01",
>       "scale_z":"0.01",
>       "offset_x":"auto",
>       "offset_y":"auto",
>       "offset_z":"auto",
>       "filename":"C:/data/forest_park/forest_park_orig_dtm.laz"
>     }
>   ]
> }
> _______________________________________________
> pdal mailing list
> pdal at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/pdal
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/pdal/attachments/20180413/c01bb866/attachment.html>