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

[Chase, Andrew]

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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