It's about the https://en.wikipedia.org/wiki/Discrete_cosine_transform https://en.wikipedia.org/wiki/Discrete_cosine_transform . > (subtitle) His digital-compr

It's about the https://en.wikipedia.org/wiki/Discrete_cosine_transform https://en.wikipedia.org/wiki/Discrete_cosine_transform . > (subtitle) His digital-compression breakthrough helped make JPEGs and MPEGs possible Technically, the DCT isn't restricted to only digital compression. The DCT performs a matrix multiplication on a real vector, giving a real vector as output. You can perform a DCT on a finite sequence of analog values if you really wanted to, by performing a specific weighted sum of the values to yield a new sequence of analog values.