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Guru

Join Date: Dec 2016
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Imagery Encoded in Sound Spectra

02/06/2017 11:50 PM

One of the better examples I've seen of encoding images in sound spectra - an example of steganography (lit. 'concealed writing'). The bulk of the music is below 5 kHz, most of the imagery above that.

Vertical axis: frequency, horizontal axis: time

As I am completely deaf above 8 kHz, I've no idea what these images sound like, but I like the music.

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Guru

Join Date: Sep 2016
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#1

Re: Imagery Encoded in Sound Spectra

02/07/2017 2:56 AM

Once in a plane just about when I had a nap, I heard that intro sound clearer in my ears and made me wake up.

This is interesting.

I bet the NSA are masters of this stuff. ELF penetrates the ground and the oceans right?

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#2
In reply to #1

Re: Imagery Encoded in Sound Spectra

02/07/2017 3:48 AM

Yes, in the ocean at least to operating depth in the case of subs. Varying depths on land, depending the soil & rock conductivity.

Because of their very low frequency, ELF radio signals cannot convey data very quickly. They cannot carry voice or music, for example.

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Guru

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#3
In reply to #2

Re: Imagery Encoded in Sound Spectra

02/07/2017 4:32 AM

EAM are are not complex messages. 50 baud is easily sufficient.

Music could probably even be transmitted....to be reconstructed as sheet music to be played aboard, though I am having difficulty imagining what attack options (limited or major) would necessitate music for communication.

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Guru

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#4

Re: Imagery Encoded in Sound Spectra

02/07/2017 4:38 AM

The higher frequencies through much of the video sound a lot like cicadas or somewhat like a frog pond sped up a bit.

I suppose that will only help if you have not always been deaf above 8 kHz.

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Guru

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#5

Re: Imagery Encoded in Sound Spectra

02/07/2017 9:22 AM

Interesting. It shouldn't be too difficult to generate: Just take an inverse FFT of the vertical scans of the pictures you want to convert to time series and add to the music audio. It looks like it might be a fun project to try sometime.

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Guru

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#7
In reply to #5

Re: Imagery Encoded in Sound Spectra

02/07/2017 2:06 PM

There are several apps available that do this. This one is a good one and has lots of other great features as well:

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Guru

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#8
In reply to #7

Re: Imagery Encoded in Sound Spectra

02/07/2017 7:44 PM

That is pretty cool.

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#6

Re: Imagery Encoded in Sound Spectra

02/07/2017 1:55 PM

Muy trippy man....

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