Downscaling raster maps: Difference between revisions

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(so you may need to use e.g. {{cmd|r.fillnulls}} first), and it also requires that you
(so you may need to use e.g. {{cmd|r.fillnulls}} first), and it also requires that you
can fit the entire raster in memory (so it isn't suitable for very high resolution data).
can fit the entire raster in memory (so it isn't suitable for very high resolution data).
See also [[Interpolation]]


[[Category: FAQ]]
[[Category: FAQ]]
[[Category: Raster]]

Latest revision as of 00:56, 6 September 2014

Question

What is be the recommended way to downsample a raster map?

Answer

The "best" way is subjective, but the main options are r.resamp.interp, r.resamp.stats, r.resamp.rst, r.mfilter.fp, or any combination of those.

Another option is to use i.fft followed by i.ifft with a MASK applied. However, that requires that your raster contains no null cells (so you may need to use e.g. r.fillnulls first), and it also requires that you can fit the entire raster in memory (so it isn't suitable for very high resolution data).

See also Interpolation