I am learning FFT for processing images with Matlab. I have already know some basic stuff but for the product of the results of two FFT, I do not quite understand.
So I want to know what will happen after we multiply the results of the Fast Fourier Transform. Can someone provide me with the example?
Multiplication in the frequency domain is equivalent to convolution in the spatial domain.
This is typically exploited when you have a large filter kernel and an image that you want to convolve with this filter. Instead of performing the convolution directly (which can be computationally expensive for large kernels) the FFT of the image and the (padded) filter kernel is taken, the two are multiplied and an inverse FFT is applied to the product.
