Hi,

Thanks to interoperability tests led by Brian Osborn from the sample GeoPackage 
with 
elevation data I generated, he spotted a more general issue with the 
registration of raster 
tiles that can cause spatial registration to be wrong when GDAL generated 
raster .gpkg are 
read by other implementations (to give full credit i think Brad Hards noticed 
this earlier)

I've fixed the issue in trunk and 2.1 branch per
https://trac.osgeo.org/gdal/ticket/6826

So if you need to ensure interoperability with other implementations, you'd 
better fetch the 
fix and regenerate your productions.

Note: You don't necessarilty need to regenerate the whole .gpkg, but you need 
to correct the 
content of gpkg_tile_matrix, so that for zoom_level = Z > 0 :
matrix_width(Z) = 2^Z * matrix_width(zoom_level=0)
matrix_height(Z) = 2^Z * matrix_height(zoom_level=0)

This is only when using no overview or power-of-two overviews. For non 
power-of-two 
overviews (which is an extension), I think there might be still issues.

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com
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