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Show HN: Small C Program to Convert Photos to Audio

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Re: Show HN: Small C Program to Convert Photos to Audio

#3
Very interesting. I wonder how it would cope with some noise -- for example playing the resultant file and recording it with a microphone for example.

I suspect there will be content lost at the bottom and the top of the image depending on the frequency response of the microphone/speaker.

Re: Show HN: Small C Program to Convert Photos to Audio

#4
post #3

Very interesting. I wonder how it would cope with some noise -- for example playing the resultant file and recording it with a microphone for example. I suspect there will be content lost at the bottom and the top of the image depending on the frequency response of the microphone/speaker.

I would expect to see the frequency response of the speaker + mic combination show up as darker and lighter horizontal bands in the image (since these spectrograms are plotted with frequency on the y axis). It might look really cool!

Edit: depending on the time alignment / phase response of the speakers, you might see the low frequency parts of the image get distorted to the right.

Re: Show HN: Small C Program to Convert Photos to Audio

#5
post #4
post #3

Very interesting. I wonder how it would cope with some noise -- for example playing the resultant file and recording it with a microphone for example. I suspect there will be content lost at the bottom and the top of the image depending on the frequency response of the microphone/speaker.

I would expect to see the frequency response of the speaker + mic combination show up as darker and lighter horizontal bands in the image (since these spectrograms are plotted with frequency on the y axis). It might look really cool! Edit: depending on the time alignment / phase response of the speakers, you might see the low frequency parts of the image get distorted to the right.

Give it a try! The output file contains both very low frequencies and also frequencies up to Nyquist, in this case 24kHz.

Re: Show HN: Small C Program to Convert Photos to Audio

#6
post #4

Earlier quoted context omitted.

I would expect to see the frequency response of the speaker + mic combination show up as darker and lighter horizontal bands in the image (since these spectrograms are plotted with frequency on the y axis). It might look really cool! Edit: depending on the time alignment / phase response of the speakers, you might see the low frequency parts of the image get distorted to the right.

Give it a try! The output file contains both very low frequencies and also frequencies up to Nyquist, in this case 24kHz.

I'll try to give it a shot! What are you using to generate the spectrograms?

Re: Show HN: Small C Program to Convert Photos to Audio

#8
post #6

Earlier quoted context omitted.

Give it a try! The output file contains both very low frequencies and also frequencies up to Nyquist, in this case 24kHz.

I'll try to give it a shot! What are you using to generate the spectrograms?

  sox -c 1 -r 48000 -b 32 -e float -t raw out.raw -n spectrogram

Re: Show HN: Small C Program to Convert Photos to Audio

#9
Aphex Twin had hidden spectrogram images in some of his tracks in the past, unfortunately I think they are not well preserved by multiple steps of compression/reencoding to youtube videos.

https://www.google.de/search?q=Aphex+Twin+Spectrograph&tbm=i...

https://youtu.be/M9xMuPWAZW8?t=5m31s

Re: Show HN: Small C Program to Convert Photos to Audio

#10
I got some very interesting results from feeding fractal images into a program like this a few years back - unfortunately, I don't have the resulting sounds, but you pick less busy images with filaments, and adjust the contrast - the result is very organic. Must have a go with this ...
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