Using FFT for data compression step is this a lossy method?

[tojeena]

Using FFT for data compression step is this a lossy method?

 

[thylacine1975]

Not necessarily - it depends what you do with the FFT output. If you threshold it/quantize it/throw something away, then yes it is.
Alternatively, if you preserve *all* of the phase/frequency output data, and use it to reconstruct your original signal via the IFFT, then no it's not.

The FFT is simply a transform, and doesn't change the overall signal (information) entropy - it just moves it around. It's not lossy unless you start throwing information away.

 

[tojeena]

Not necessarily - it depends what you do with the FFT output. If you threshold it/quantize it/throw something away, then yes it is.
Alternatively, if you preserve *all* of the phase/frequency output data, and use it to reconstruct your original signal via the IFFT, then no it's not.

The FFT is simply a transform, and doesn't change the overall signal (information) entropy - it just moves it around. It's not lossy unless you start throwing information away.

Thank you,I would like to use fft for image as a pre processing step for compression using rice codes.