[gdal-dev] VRT and overviews

Oyvind Idland oyvind.idland at gmail.com
Wed Apr 4 11:05:21 EDT 2012


Ok, thanks, good to know.

-- oyvind

On Wed, Apr 4, 2012 at 3:24 PM, Dmitry Baryshnikov <polimax at mail.ru> wrote:

>  04.04.2012 16:57, Oyvind Idland написал:
>
> How do I get overviews to work with VRT datasets ?
>
> What I do is
>  - creating a .vrt with additional alpha band + nodata using gdalbuildvrt
> (wrapping an existing TIFF)
>  - creating overviews using gdaladdo. I then get an external .ovr file.
>  - creating a new TIFF from the VRT
>
> First, it seems that the .vrt does not get updated, as there is no
> <Overview> tags. I then tried to manually add <Overview> for each band,
> but the output TIFF does not have overviews in it.. just the original
> bitmap and a mask for it.
>
> Example:
>
> gdalbuildvrt _r-32-2-4776-64728.vrt -overwrite -addalpha -srcnodata 0
> -vrtnodata 0 r-32-2-4776-64728.tif
>
> gdaladdo _r-32-2-4776-64728.vrt 2 4 8 16 32 64
>
> gdal_translate -of GTiff -co COMPRESS=JPEG -co JPEG_QUALITY=80 -co
> PHOTOMETRIC=YCBCR -b 1 -b 2 -b 3 -mask 4 -co COPY_SRC_OVERVIEWS=YES
> --config GDAL_TIFF_INTERNAL_MASK YES _r-32-2-4776-64728.vrt
> output\r-32-2-4776-64728.tif
>
>
> Also, I tried to add overviews embedded inside the source tiff (wrapped in
> the same .vrt), but still no overviews in the output.
>
> Note, that what I'm really trying to do, is to create TIFF with JPEG
> compression, and adding a mask that is not "contaminated" with jpeg
> artifacts.
>
> What am I doing wrong ? :)
>
>
> -- oyvind
>
>
> _______________________________________________
> gdal-dev mailing listgdal-dev at lists.osgeo.orghttp://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>  This is the bug and I'm working to fix it.
> I think this bug are mentioned in such tickets
> http://trac.osgeo.org/gdal/ticket/2076 and
> http://trac.osgeo.org/gdal/ticket/3482
>
> Regards,
>     Dmitry
>
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> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
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