Jay, Can you provide a sample file that gives this error?
On Tue, Feb 22, 2011 at 1:56 AM, Jay Jennings <jennings....@geoeye.com>wrote: > Hello list, > > (using GDAL 1.8.0) I am trying to create a 32:1 down-sampled overview of a > GeoTiff satellite image. My first thought was gdal_translate, with args > such as “-outsize 3.125% 3.125%”… which produces surprisingly high quality > given the absence of a resampling option. However I’m looking for a > downsampling scheme that creates a result pixel by averaging all relevant > source pixels (I know, for 32:1 downsample, that means 1024 source pixels > for each result pixel !) with the hope of an output that is not “speckled” > or “grainy” insofar as possible. > > > > I also looked at gdaladdo, which does have the “-r average” resampling > option… the guidance at gdal.org seems to suggest that it can produce a > 32:1 GeoTIFF external overview with a command like this: > > > > gdaladdo -r average -ro XXXXX.tif 32 > > > > But that produces a surprising error message, namely: > > ERROR 4: `XXXXX.tif.ovr' does not exist in the file system, and is not > recognised as a supported dataset name. > > > > Am I barking up the wrong tree with gdaladdo for this purpose ? Anybody > have any suggestions for highest-quality down-sampling ? Thanks in advance. > > > > --Jay Jennings > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- Best regards, Chaitanya kumar CH. /tʃaɪθənjə/ /kʊmɑr/ +91-9494447584 17.2416N 80.1426E
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