ERROR: Unable to open real-image in the 'cell_misc' directory. Raster map
probably wasn't created by i.fft[[BR]]
# questions
Is it fair enough to ask for this support?[[BR]]
Or is there a reason why _r.mfilter_ alters the i.fft-products in such a
way that _i.ifft_ can't handle?
#549: r.mfilter should _respect_ i.fft outputs for use with i.ifft
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Reporter: nikos | Owner: grass-dev@lists.osgeo.org
Type: defect | Status: new
Priority: major | Milestone: 6.4.0
Component: Raster | Version: svn-develbranch6
Resolution: | Keywords: i.fft, r.mfilter, i.ifft
Platform: Unspecified | Cpu: Unspecified
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Comment (by glynn):
Replying to [ticket:549 nikos]:
> Is it fair enough to ask for this support?[[BR]]
It's already present in 7.0, but the interface had to be changed (separate
maps for the real and imaginary components), so it's unlikely to be back-
ported.
> Or is there a reason why _r.mfilter_ alters the i.fft-products in such
a way that _i.ifft_ can't handle?
i.fft stores the actual frequency-domain data in auxiliary data files. The
output map only exists for viewing with d.rast. Apart from anything else,
a raster map can only store real values, and the FFT results are complex
values.
i.ifft operates upon the auxiliary data files, not the map itself, so it
only works with maps which were generated by i.fft. The only processing
which can be performed on the frequency-domain data is to apply a mask
(i.ifft explicitly applies the MASK raster if it exists).