[gdal-dev] I cannot clean overviews from GeoTIFF

[Rahkonen Jukka]

Hi,

So now we have the right question: how to remove overviews from cloud optimized GeoTIFF.

First confirm your findings:

gdal_create -of cog -outsize 1000 1000 cog.tif
0...10...20...30...40...50...60...70...80...90...100 - done.

test1:
gdaladdo cog.tif
ERROR 6: cog.tif: Cannot add external overviews when there are already internal overviews
Overview building failed.

test2
gdaladdo -clean cog.tif
ERROR 6: cog.tif: Cannot add external overviews when there are already internal overviews
Cleaning overviews failed.

All right, COG is a GeoTIFF and only metadata tells that it is also COG

Image Structure Metadata:
  LAYOUT=COG
  COMPRESSION=LZW
  INTERLEAVE=BAND

So, let's try to remove the metadata. No success but an interesting message:

gdal_edit -unsetmd cog.tif
File cog.tif has C(loud) O(ptimized) G(eoTIFF) layout. Updating it will generally result in losing part of the optimizations (but will still produce a valid GeoTIFF file). If this is acceptable, open the file with the IGNORE_COG_LAYOUT_BREAK open option set to YES.

Let's try the suggested option:

gdaladdo -clean cog.tif -oo IGNORE_COG_LAYOUT_BREAK=yes

Success!

Now it is your turn to suggest improvements to COG driver manual page and to the error messages of gdaladdo.

-Jukka Rahkonen-

________________________________________
Lähettäjä: Javier Jimenez Shaw
Lähetetty: Maanantai 12. toukokuuta 2025 16.48
Vastaanottaja: Rahkonen Jukka
Kopio: gdal dev
Aihe: Re: [gdal-dev] I cannot clean overviews from GeoTIFF

Apparently it is related with COG:$ gdal_translate -of COG foo.tif foo.cog.tifInput file size is 1000, 10000...10...20...30...40...50...60...70...80...90...100 - done.$ gdaladdo -clean --debug ON foo.cog.tif GDAL: GDALOpen(foo.cog.tif, this=0x15900ae00) succeeds as GTiff.GTiff: ScanDirectories()GTiff: Opened 500x500 overview.GTiff: File open for read-only accessing, creating overviews externally.ERROR 6: foo.cog.tif: Cannot add external overviews when there are already internal overviewsCleaning overviews failed.GDAL: GDALClose(foo.cog.tif, this=0x15900ae00)