My question is: assuming I have a 512 bands spectrum, what would be the recommended interpolation algorithm to rescale the spectrum to 20 bands, for user visualization? Is a simple bilinear filter good enough?
To make my question clearer: I am interested in what the state of the art is regarding this today: what professional tools are used? An answer mentions sinc interpolation which will likely be high quality, but also maybe computationally expensive? Is it the best trade-off for a generic audio visualization tool?