[Numpy-discussion] Horizontal lines in diffraction image (NumPy FFT)
Stéfan van der Walt
stefan@sun.ac...
Wed Aug 6 05:33:21 CDT 2008
2008/8/6 Matthieu Brucher <matthieu.brucher@gmail.com>:
> Exactly. Using FFT to do a convolution should be done after some
> signal processing readings ;)
When you convolve two signals, of lengths N and M, you need to pad the
FFTs to length (N+M-1) before multiplication.
You can take a look at my linear position-invariant filtering code at:
http://mentat.za.net/hg/filter
To construct a Gaussian filter, for example, you do:
>>> def filt_func(r,c):
return np.exp(-np.hypot(r,c)/1)
>>> filter = LPIFilter2D(filt_func)
You may then apply it on data by doing `filter(data)`. I also
implemented inverse filtering, which can be accessed using
`filter.inverse` and `filter.wiener`.
Regards
Stéfan
More information about the Numpy-discussion
mailing list