Yes, with sufficient padding, you can compute a linear convolution (of finite length vectors) exactly using a circular convolution. The FFT might introduce a little noise in the result, but that is all.
On Tuesday, 4 March 2014 13:12:48 UTC+1, Oliver Lylloff wrote: > > Well ok, > > Maybe I misunderstood the whole thing then but since fft assumes periodic > input then I don't see how it can be a linear convolution. I guess > Base.conv2 probably uses zero-padding to reduce wrap-around but in theory > it would still be a circular convolution. I'll read up on it :) > > Best, > Oliver > > Den tirsdag den 4. marts 2014 13.07.20 UTC+1 skrev Andreas Noack Jensen: >> >> Both conv and conv2 are linear convolutions but the implementations use >> the fft. Maybe the documentation could be more clear on that. >> >> >> 2014-03-04 13:01 GMT+01:00 Oliver Lylloff <[email protected]>: >> >>> Thanks Tim. >>> >>> Can't believe I missed that - been working with Images.jl all day. Nice >>> job by the way, very useful. >>> >>> Best, >>> Oliver >>> >>> Den tirsdag den 4. marts 2014 12.48.01 UTC+1 skrev Tim Holy: >>> >>>> Images.jl's imfilter might be what you want. >>>> --Tim >>>> >>>> On Tuesday, March 04, 2014 03:38:15 AM Oliver Lylloff wrote: >>>> > Hello all, >>>> > >>>> > Is anyone aware of a linear convolution implementation? >>>> > The Base.conv and Base.conv2 functions are implemented with fft which >>>> makes >>>> > them circular convolution functions (as far as I know). >>>> > >>>> > I'm looking for something alike Matlabs conv2 or SciPys >>>> signal.convolve2d. >>>> > >>>> > Should be straightforward to implement though. >>>> > >>>> > Best, >>>> > Oliver >>>> >>> >> >> >> -- >> Med venlig hilsen >> >> Andreas Noack Jensen >> >
