Downscaling raster maps: Difference between revisions
Jump to navigation
Jump to search
(new FAQ) |
mNo edit summary |
||
| (2 intermediate revisions by one other user not shown) | |||
| Line 1: | Line 1: | ||
''' | '''Question''' | ||
''' | What is be the recommended way to downsample a raster map? | ||
r.resamp.interp, r.resamp.stats, r.resamp.rst, r.mfilter.fp, or any | |||
'''Answer''' | |||
The "best" way is subjective, but the main options are | |||
{{cmd|r.resamp.interp}}, {{cmd|r.resamp.stats}}, {{cmd|r.resamp.rst}}, {{cmd|r.mfilter.fp}}, or any | |||
combination of those. | combination of those. | ||
Another option is to use i.fft followed by i.ifft with a | Another option is to use {{cmd|i.fft}} followed by {{cmd|i.ifft}} with a MASK applied. | ||
However, that requires that your raster contains no null cells (so you | However, that requires that your raster contains no null cells | ||
may need to use e.g. 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 | can fit the entire raster in memory (so it isn't suitable for very high resolution data). | ||
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