[gdal-dev] GPKG: int16 with scale

[Idan Miara]

Got it, thanks for your quick response!

On Mon, 10 Dec 2018 at 16:59, Even Rouault <even.rouault at spatialys.com>
wrote:

> On lundi 10 décembre 2018 16:29:09 CET Idan Miara wrote:
> > Hi,
> >
> > I'm trying unsuccessfully to save Int16 dataset with scale != 1.0 in
> GPKG.
> >
> > If I understand correctly the remark about "Tiled gridded coverage data"
> > here:
> > https://www.gdal.org/drv_geopackage_raster.html
> > I expect offset and scale for Int16 to be supported in gdal.
> >
> > I tried to gdal_translate an int16 dataset from GTiff to GPKG and the
> scale
> > value is lost (at lease as far as QGIS is concerned).
> > I also translated the output gpkg back to GTiff and verified that the
> scale
> > is 1.0 instead of 2.0 as in my original GTiff.
>
> Yes, the Scale and Offset concepts as exposed by GDAL are ignored in
> reading
> or writing by the GeoPackage driver and haven't been mapped to the
> corresponding GPKG concepts. I guess this could be done, but for now the
> GPKG
> scale and offset have been kept as internal details when forcing a PNG
> encoding for a Float32 data type, and the driver will automatically set
> and
> apply scale and unscale, but not expose the raw values and the scale and
> offset metadata values.
>
> For now, the solution is to use gdal_translate -unscale so as to convert
> the
> raw values into values after applying scale and offset.
>
> Even
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com
>
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