Matteo Sisti Sette escribió:
Charles Henry escribió:
The interpolation, since it cannot be an ideal interpolation, may introduce other noises or artifacts, not aliasing as far as I can see.
There's two parts to it, aliasing (stopband) and non-flat frequency response (passband).
Well this seems o be a matter of terminology. I think you call "aliasing" a wider class of artifacts than I was taught to call "aliasing".
Oh no, maybe not. I read your explanation more carefully and of course, the non-perfectness of the interpolation process (i.e. its non-zero frequency response in the stop band) is responsible for the persistence of attenuated copies of the original spectrum at multiples of the original sampling rate, which then appear aliased into the passband when the signal is sampled again at a different rate.
This is what's going on when discontinuities in the interpolated signal cause noise at high frequencies, isn't it?