Fastest method for calculating convolution

Question

Anybody know about the fastest method for calculating convolution? Unfortunately the matrix which I deal with is very large (500x500x200) and if I use convn in MATL

Answer 1

You could try the overlap-add and overlap-save methods. They involve breaking up your input signal into smaller chunks and then using either of the above methods.

An FFT is most likely - and I could be wrong - the fastest method, especially if you are using built-in routines in MATLAB or a library in C++. Apart from that, breaking the input signal into smaller chunks should be a good bet.