[Gdal-dev] How to best perform raster cell aggregation

[Dylan Beaudette]

Hi Andrew, nice to see someone from the aquarium posting to the GDAL list!

i would highly recommend a GDAL+GRASS approach to your problem : GDAL
for the conversion and import / GRASS for the aggregation / analysis.
If possible, get  the CVS version of GRASS which contains several new
resampling commands.

Cheers,

Dylan

On 2/12/07, Chase, Andrew <achase at mbari.org> wrote:
>
>
>
> Hi Folks,
>
> I'm working with raster files, starting in the NetCDF format, but then
> moving them to .tif and .png based on how the user will need to manipulate
> them. One seemingly simple thing that I've been unable to find a simple
> solution for is resampling the data with an aggregation algorithm. For
> instance, I'd like to go from a 10 meter cell size to a 100 meter cell size
> where the value for a 100m cell is the sum of all the 10m cells that the
> 100m cell now represents. I have a very sparsely populated dataset, so
> averaging on resample tends to just push everything towards zero. What I'm
> looking for is the ability to see where very small data points exist when
> zoomed out.
>
> I thought gdaladdo would be a good option for this, but it looks like is
> only for adding overview's to an already existing file and not for creating
> new files. Could I add an overlay to a tif and then extract just that
> overlay image into, say, a png?
>
> Thanks,
> Andrew
>
> Andrew C. Chase
> Software Engineer
> Monterey Bay Aquarium Research Institute
> (831) 775-1865 :: Work
> (831) 419-8566 :: Cell [NOTE: New number as of May 22, 2005]
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