[Matrix-SIG] general 2D convolution, again.

Dirk Engelmann Dirk.Engelmann@IWR.Uni-Heidelberg.De
Fri, 27 Mar 1998 10:52:46 +0100 (CET)

On Thu, 26 Mar 1998, David Ascher wrote:

> This topic comes up repeatedly, but I haven't seen a good answer yet.

Some time ago I posed the same question.

> Problem: doing 2D convolutions with non-square and different shape arrays
> is (from what I've read) not doable using FFT multiplication.  Has anyone
> coded such a convolution in either straight NumPy or using a C extension
> module?  Linear, circular, with sweet-spot setting, etc?  

I need it  for image processing - and for large images (matrices) 
FFT is quite usefull - but not for non-square shape.
If done it in my C++ library with swig interface to Python. But it's 
not that flexible (Linear, circular, ...).

I would like to have it in NumPy very much!

> If not, I'll probably end up writing one, but it's likely to be buggy for
> a while...

Dirk Engelmann