Re: [music-dsp] Cheap spectral centroid recipe

From: "Ethan Duni" Date: Thu, February 18, 2016 4:48 pm -- > I've noticed > in my (cursory) searches that some people use amplitude spectra and others > use power spectra, but the only

Re: [music-dsp] Cheap spectral centroid recipe

I was kind of hoping someone would chime in with a reference to a publication of some tests comparing different spectral centroid methods, showing how well they match some subjective ratings of "brightness" or whatever, for various signal classes. This doesn't seem particularly difficult, although

Re: [music-dsp] Cheap spectral centroid recipe

I don't think I got the message containing this question: *again, Evan, what i would like to hear from you is, given your offered algorithm for spectral centroid, if you play, say a piano into it, one note at a time, does C# have a 6% greater spectral centroid or 12% higher than C? or less than

Re: [music-dsp] Cheap spectral centroid recipe

> > again, Evan, what i would like to hear from you is, given your offered > algorithm for spectral centroid, if you play, say a piano into it, one note > at a time, does C# have a 6% greater spectral centroid or 12% higher than > C? or less than 6%? It seems to me, with the sqrt in the latest

Re: [music-dsp] Cheap spectral centroid recipe

Original Message Subject: Re: [music-dsp] Cheap spectral centroid recipe From: "Evan Balster" Date: Thu, February 18, 2016 1:55 pm To: music-dsp@music.columbia.edu

Re: [music-dsp] Cheap spectral centroid recipe

*To use log magnitude you'd first have to normalize it to look like a probability density (non-negative, sums to one). Meaning you add an offset so that the lowest value is zero, and then normalize. Obviously that puts restrictions on the class of signals it can handle - there can't be any zeros

Re: [music-dsp] Cheap spectral centroid recipe

>Weighting a mean with log-magnitude can quickly lead to nonsense. To use log magnitude you'd first have to normalize it to look like a probability density (non-negative, sums to one). Meaning you add an offset so that the lowest value is zero, and then normalize. Obviously that puts restrictions

Re: [music-dsp] Cheap spectral centroid recipe

Original Message Subject: Re: [music-dsp] Cheap spectral centroid recipe From: "Evan Balster" Date: Thu, February 18, 2016 10:42 am To: music-dsp@music.columbia.edu

Re: [music-dsp] Cheap spectral centroid recipe

Weighting a mean with log-magnitude can quickly lead to nonsense. Trivial examples: - 0dB sine at 100hz, 6dB sine at 200hz --> log centroid is 200hz - -6dB sine at 100hz, 12dB sine at 200hz --> log centroid is 300hz (!) Sanfillipo's adaptive median finding technique is still applicable,