Stefan, Did I pad my example incorrectly? Both images were upped to the larger nearest power of 2 (256)...
Does the scipy implementation do this differently? I thought that since FFTW support has been dropped, that scipy and numpy use the same routines... Thanks! Chris 2009/5/11 Stéfan van der Walt <ste...@sun.ac.za> > Hi Chris > > 2009/5/11 Chris Colbert <sccolb...@gmail.com>: > > When convolving an image with a large kernel, its know that its faster to > > perform the operation as multiplication in the frequency domain. The > below > > code example shows that the results of my 2d filtering are shifted from > the > > expected value a distance 1/2 the width of the filter in both the x and y > > directions. Can anyone explain why this occurs? I have been able to find > the > > answer in any of my image processing books. > > Just as a reminder, when doing this kind of filtering always pad > correctly. Scipy does this in > > scipy.signal.fftconvolve > > I've also got some filtering implemented in > > > http://mentat.za.net/cgi-bin/hgwebdir.cgi/filter/file/e97c0a6dd0ea/lpi_filter.py > > Regards > Stéfan > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
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