spectrophoto is an interesting project, it turns your images into raw audio files, and the images can be viewed on the spectrogram.

Here is an example, used on this blog’s logo:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDFsg7KdfQJwluzsq073CcWJNkNsTIAN50oixJWEOMIra43VYCZveT9LsH8v042O4n3_Ua5yuSqV1rABzDKx0TzojjYdsPzQD0s0YXNwiVBz7gUckrCUAcDEk-U-lVyxP9eNAg7vLtXlE/s800/LYJ-200.png.raw.png

You can listen to generate audio file, which I have converted into Ogg. Another example on Clip smile (audio):

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjpQIOtjrYvJangA63Q9O1kXwY7DR4yVf39CMfos1b2-7kJVFi4VlN9vzsmiQUUKnNEna-MMW2B1lMphu9b58zieuiNfGLq3IoccveJ4CKhKBlS7XEW5X2-fmIZdbO3nGN5aew_9QOK_yA/s800/Clip%252520smile-200x200.jpg.raw.png

There is no options, just input and output files. Don’t know any practical application for this program, perhaps hiding something in images, then in audios? I wonder if you can convert back to image?

spectrophoto was created by Kyle Swanson in April, 2015, written in C99 and licensed under the MIT License. You might also want to check out ascii-audio from the same author, a text version input.