Re: Extremely precise sonogram ?


Forums > MaxMSP > Extremely precise sonogram ?
March 30, 2010 | 12:04 am

But seriously, i’m sure this reassignment method is only the 3/5 in the way to the best sonogram that can be done.

These artifacts produced by the reassignment method could be almost cleared by multiplying some different FFT-variously-sized reassigned sonograms… Because from one FFT size to another, these artifacts are moving… but not the pitched content… (also, this should show a better distinction between pitched and noise content, you see?)

I’m lost in front of the math under this reassignment method. Plus it’s kind of slower to compute…

Any interested C-external developers, to make an efficient [jit.reassignedFFT] object from LORIS C libraries ?

I’m also wondering if any voronoi jitter effect could approach this in some way, i asked this on the jitter forum : http://cycling74.com/forums/topic.php?id=25579

This reassignment method, associated with freq&time overlaps, and associated with the idea of blending different FFT-sizes, could get really cruel with this "Heisenberg’s uncertainty principle", and open useful new possibilities, like :

- Very fine polyphonic pitch tracking… There is already the [transcribe~] external, a pioneer, but works really bad. But if you have fine harmonic pitch tracking (see another pitch tracking example in the image/mp3 below), then, even in a polyphonic messy sonogram, one could do greats things : Imagine that you divide vertically the size of the 16384* lines jitter sonogram by 2, by 3, by 4, by 5, etc… harmonics. (considering that most musicals sounds have true harmonics with negligible inharmonicity), intelligently add*multiply all these (antialiased) jitter matrixes ( (H1+H2+H3+H4…) * ((H1+f)*(H2+f)*(H3+f)*(H4+f)*…) where f is a kind of "noise factor" to adjust ) …and get damned cool, understandable, polyphonic pitch tracking sonogram !

- And maybe – only when we’ll have 20 Ghz laptops… – start to dream about the mythical "demixer"…

* (let’s say 1024 * 32 frequency overlap = 16384)

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