[gdal-dev] GDAL Interpolation Help

[Scott]

Averaging rasters is a common task. Often I see developers write many 
lines of python to do simple tasks like this. The following GDAL command 
should give you the results you're looking for:

gdal_calc.py -A input1.tif -B input2.tif --outfile=result.tif 
--calc="(A+B)/2"

The above command was taken directly from the gdal_calc.py man page:
https://gdal.org/programs/gdal_calc.html


On 9/27/23 10:44, Bill Myers via gdal-dev wrote:
> Hi,
> I am new to working with GDAL. We are trying to spatially interpolate 
> Numerical Weather Prediction (NWP) model data to an arbitrary location, 
> i.e. lat/lon. We have been using gdal_translate but have been getting 
> unexpected results.
> We have used the resampling method called "average". In this toy 
> example, we are trying to resample to a grid with twice the density of 
> the input data set. As can be seen in the image in the link below, the 
> values at the points that match the input points agree with the input 
> values. That's good. However, the interpolated values do not match our 
> expectations. We would expect the interpolated value at the midpoint 
> (directly between two input points) to be the average of those two input 
> points. As can be seen, this is not the case.
> Can someone please help us understand what we might be doing 
> incorrectly? Also, does GDAL have the functionality that we are looking for?
> Thanks for your help.
> -b
> https://pasteboard.co/uumLD4JtNmp3.png 
> <https://pasteboard.co/uumLD4JtNmp3.png>
> 
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