[gdal-dev] Re: Switching from ArcGIS to GDAL

[Frank Warmerdam]

On 12-02-25 11:02 AM, jgamble wrote:
> Does gdaladdo support mosaic datasets?  If so, are there examples of how to
> use gdaladdo with mosaic datasets?

Jon,

GDAL does not support ArcGIS virtual mosaic format.

The gdaladdo utility can be used on conventional raster formats.  It is
also possible to build a GDAL virtual raster file which might be a mosaic
of raster files and then build overviews on it.  I believe gdalbuildvrt
is normal utility used to build .vrt mosaics.

However, whether this is suitable for your purposes will depend on
what you want to use the result for.  If you just want a freestanding
overview image of a set of images then you would be better off just
doing something like:

   gdal_merge.py -o mosaic.tif -ps 20 20 in*.tif

Assuming you want a mosaic of all in*.tif files with the output overview
mosaic with a 20m by 20m pixel size.

Note that .vrt's and their corresponding overviews may be usable in
ArcGIS (since it uses GDAL) but I am not certain and it will likely
depend on the version.

Best regards,
-- 
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