[gdal-dev] weeding out x,y,z points

Joaquim Luis jluis at ualg.pt
Thu Feb 26 13:42:10 EST 2009


> Okay, I downloaded the Manpages.
> 
> My initial reading is that blockmean and blockmedian work by averaging
> the values.

blockmedian does not do point average. It does take the median point inside each bin.
However, if the number of points inside a bin is even than it takes the average
of the two central points.

> My client says that they want the resulting data points to be
> a subset of the original data points, that is the process should
> delete points, not re-calculate new ones that are an average.

Well, you (or the client) do what you want, but that is not the
correct procedure because it may introduce aliasing. What will be the
condition to decide the reference point towards which the others
are compared?

Joaquim



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