[SciPy-User] 2d convolution

[Nico Schlömer]

> If it is much faster than the n-dimensional fft convolution

For me it is about 60(!) times faster, see the attached graph (mind
the log scaling).
I had NxN data with NxN kernels convolved.

The source code for producing the figure is attached as well.

> be worth writing a fftconvolve2
What remains to be checked is the ratio for the case where the kernel
is a lot smaller than the data. If that turns out to be equally fast,
I don't see any reason to keep the current implementation of
scipy.signal.fftconvolve.

Anyway, this may also be related to that other discussion going on
about FFTW. I'm not sure what the current status about FFT
implementations in SciPy is, but at first glance there seem to be
quite a few really, which to me seems redundant and unhelpful.

Does anyone have more insight here?

Cheers,
Nico
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