[gdal-dev] Raster attributes tables with URL raster

[Kirk Waters - NOAA Federal]

Thank you so much. I should have known that, but it wasn’t coming to my
mind.

Kirk


On Tue, Dec 16, 2025 at 4:40 PM Rahkonen Jukka <
jukka.rahkonen at maanmittauslaitos.fi> wrote:

> Hi,
>
> The http://... downloads the file, use the vsicurl method instead. Test
> with gdalinfo:
>
> gdalinfo /vsicurl/"
> https://noaa-ocs-nationalbathymetry-pds.s3.amazonaws.com/BlueTopo/BC26826R/BlueTopo_BC26826R_20241023.tiff
> "
>
> -Jukka Rahkonen-
>
>
> ________________________________________
> Lähettäjä: gdal-dev <gdal-dev-bounces at lists.osgeo.org> käyttäjän Kirk
> Waters - NOAA Federal via gdal-dev <gdal-dev at lists.osgeo.org> puolesta
> Lähetetty: Tiistai 16. joulukuuta 2025 22.32
> Vastaanottaja: gdal-dev at lists.osgeo.org <gdal-dev at lists.osgeo.org>
> Aihe: [gdal-dev] Raster attributes tables with URL raster
>
> Dear GDAL gurus,I'm struggling a little with raster attribute tables if
> the file is remote. They don't seem to be recognized. For example, there is
> a file (
> https://noaa-ocs-nationalbathymetry-pds.s3.amazonaws.com/BlueTopo/BC26826R/BlueTopo_BC26826R_20241023.tiff)
> with a side-car *.aux.xml file that has a RAT for band 3. If I pull down
> those two files locally and run gdalinfo on it, I can see the RAT. If I do
> the same with the URL, no attributes show. My goal is to grab the RAT in
> python, but this test script also gets nothing for each band (each band has
> a NoneType RAT instead of a gdal.RasterAttributeTable).from osgeo import
> gdalgdal.UseExceptions()url='
> https://noaa-ocs-nationalbathymetry-pds.s3.amazonaws.com/BlueTopo/BC26826R/BlueTopo_BC26826R_20241023.tiff'ds
> = gdal.Open(url)for band_id in range(ds.RasterCount):    band =
> ds.GetRasterBand(band_id+1)    rat = band.GetDefaultRAT()    print(f"Band
> {band_id+1} has rat type {type(rat)}")Is there something I'm doing wrong?
> I've tried the various options for GDAL_DISABLE_READDIR_ON_OPEN, but they
> haven't changed the result.Thanks,Kirk Waters, PhD NOAA Office for Coastal
> ManagementApplied Sciences Program      coast.noaa.gov/digitalcoast
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