On 3/31/15 6:53 PM, Justin Salamon wrote:
To expand on what Ethan wrote, it sounds like what you're trying to do is zero-pad the signal: http://www.dsprelated.com/dspbooks/mdft/Zero_Padding.html That said, whilst zero padding will give you an interpolated spectrum in the frequency domain, you may still miss the "true location" of your peaks,
how so? the only mechanism for missing the "true location" would be sidelobe interference from adjacent peaks, possibly including the peak(s) in negative frequency.
and it will also increase the computational cost. Another thing to look at is re-estimating the exact location of the peaks in your spectrum using parabolic interpolation: http://www.dsprelated.com/dspbooks/sasp/Quadratic_Interpolation_Spectral_Peaks.html
quadratic interpolation of peaks (given the three discrete samples around the peak) is a good ol' standby. i use it for autocorrelation to get the period to a fractional-sample precision. but i don't see why it would be more accurate than zero-padding before the FFT.
Or, you could use the phase instead to compute the instantaneous frequency: http://en.wikipedia.org/wiki/Instantaneous_phase#Instantaneous_frequency
needs a Hilbert transformer. and you would also need to isolate the sinusoidal partial from the other partials.
i think so, anyway. -- r b-j r...@audioimagination.com "Imagination is more important than knowledge." -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
