invalid COG from GDAL 3.1.0 onwards

Not sure whether this is the right place to report this but it seems relevant as it can be reproduced using rio cogeo create and rio cogeo validate.

Use the files in validate.zip to reproduce:

rio cogeo create temp.tif cog.tif && rio cogeo validate cog.tif with GDAL 3.0.4 creates a COG and validation outputs this:

Reading input: /temp.tif
Adding overviews...
Updating dataset tags...
Writing output to: /cog.tif
/cog.tif is a valid cloud optimized GeoTIFF

whereas running the same command with GDAL 3.1.0 (also tested 3.1.1 and 3.1.2 with the same result) makes rio cogeo validate return an error:

Reading input: /temp.tif
Adding overviews...
Updating dataset tags...
Writing output to: /cog.tif
The following errors were found:
- The offset of the main IFD should be 8 for ClassicTIFF or 16 for BigTIFF. It is 192 instead
/cog.tif is NOT a valid cloud optimized GeoTIFF

Again, I guess the error rather has its origin in either GDAL itself or rasterio, however I think it is worth at least documenting it here as it affects COG creation using rio-cogeo.

I’ll investigate further on the GDAL and rasterio issue trackers but do you have a clue where the issue could be?

[rouault]

Would be nice to just be able to do GetMetadataItem("GDAL_GHOST_AREA_METADATA")

See https://github.com/OSGeo/gdal/pull/2832

[rouault]

yon’t have access to the bytes directly

you can probably relax the test on the location of the first IFD to be within the first 200 bytes or so