[gdal-dev] Append new data to GeoPackege raster table as overview

[Rahkonen Jukka (MML)]

Hi,

Let's say that I have these raster maps with 2048 m and 1024 m pixel sizes
http://kartat.kapsi.fi/files/taustakarttasarja_jhs180/taustakartta_8m/2048m/etrs89/png/Taustakartta_8milj.png
http://kartat.kapsi.fi/files/taustakarttasarja_jhs180/taustakartta_8m/2048m/etrs89/png/Taustakartta_8milj.pgw

http://kartat.kapsi.fi/files/taustakarttasarja_jhs180/taustakartta_4m/1024m/etrs89/png/Taustakartta_4milj.png
http://kartat.kapsi.fi/files/taustakarttasarja_jhs180/taustakartta_4m/1024m/etrs89/png/Taustakartta_4milj.pgw

Converting the 8milj.png into GeoPackage raster table is easy

gdal_translate -of gpkg -a_srs epsg:3067 Taustakartta_8milj.png overview.gpkg

Image goes to zoom level 2 as reported by gdalinfo:
Metadata:
  IDENTIFIER=overview
  ZOOM_LEVEL=2

But now the hard part: I would like to append the second image 4milj.png to the same layer "overview" as ZOOM_LEVEL=3 because that  map is designed for that resolution. Is it possible to do that by using some parameters of the driver http://www.gdal.org/drv_geopackage_raster.html or with some clever trick?

-Jukka Rahkonen-

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