Fourier Transforms – The Math Trick Behind MP3s, JPEGs, and Homer Simpson’s Face

Re:Fourier Transforms – The Math Trick Behind MP3s, JPEGs, a... by dwrtz on Wednesday November 06, 2013 @03:14PM (#6685178)

Awesome article! Here are two things that stuck out for me...

1.) In the first part of the article talking about decomposing a periodic signal into sinusoids of different frequencies - it would be more correct to refer to it as the Fourier _Series_, which is different from the transform.

2.) The image showing three sinusoids summing together into a non-period signal made me cringe (the sum is also periodic - that's the whole point of the Fourier Series).

[ Parent | on HN ]

Re:Fourier Transforms – The Math Trick Behind MP3s, JPEGs, a... by acjohnson55 on Wednesday November 06, 2013 @03:23PM (#6685237)

1) ...which when applied to a sampled signal, is the discrete-time Fourier transform (DTFT)

2.) It will only be periodic if there exist some frequency for which the frequencies of the sinusoids are integer multiple.

[ Parent | on HN ]