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fourier posts

Fourier's Finches: A Primer on Digital Audio

As far as I know, Jean-Baptiste Joseph Fourier never took an interest in birds, but he was a legendary mathematician who’s work enabled our modern techniques for digital audio. Fourier discovered a mathematical transformation that converts a time signal into a frequency signal. This would let us, for example, record a finch’s birdsong and decompose it to find the major frequencies. This would be useful for compressing the audio file. By studying the anatomy of the ear, you can throw away all the frequencies that the ear wouldn’t hear anyway.

Lossy Image Compression

Every time you take a picture on your phone, most of the data is thrown away. Lossy image compression is the art of throwing away what your eyes won’t notice. Note: at no point will this blog cover middle-out compression the pixels on most screens emit three different colors of light: red , green and blue . The reason those colors where chosen is that human color perception is enabled by cone cells, with cells that respond to red, green and blue light.