[gdal-dev] gdalwarp RPC_DEM NoData value

[Even Rouault]

Le lundi 27 juin 2016 17:42:23, Benjamin Deschamps a écrit :
> Hi,
> 
> In reference to this older thread:
> https://lists.osgeo.org/pipermail/gdal-dev/2012-April/032343.html
> 
> I encountered the same issue; I'm fairly certain that the issue is due to
> invalid RPC_DEM values, in my case, NoData values of -32768. Setting the
> NoData value in the GeoTiff has no effect either, gdalwarp still attempts
> to apply the RPC model to these points. If I replace all these values with
> "0", the RPC orthorectification is successful, probably because zero is a
> more sensible elevation.
> 
> Is there a way to consider NoData pixels in the RPC_DEM, and preventing
> them from being used for locating the output extents?

Benjamin,

You can use the RPC_DEM_MISSING_VALUE warping option :
http://www.gdal.org/gdal__alg_8h.html#af4c3c0d4c79218995b3a1f0bac3700a0

However that probably doesn't cover your "preventing them from being used for 
locating the output extents" requirement.

So filling nodata values as you did is probably the only option. You can also 
do it with a VRT file with :
gdalbuildvrt -hidenodata -vrtnodata 0 nodata_replaced_with_zero.vrt nodata.tif 

Even

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