U članku piše da je potreba za oversamplingom nastala zbog nesavršenosti filtera:
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Pošto filteri nisu savršeni i ne mogu u samo nekoliko herca potpuno smanjiti signal, koristi se oversampling. Tada je frekvencija odabiranja nesto veca od 2x, te je recimo CD standard 44.1 kHz (44100 semplova u sekundi), iako treba da prenesemo samo frekvencije do 20 kHz radi čujnog područja uha, dakle 2.05 kHz je ostavljeno radi nesavrsenosti filtra.
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Evo šta kaže vikipedija:
http://en.wikipedia.org/wiki/Oversampling#Example
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For example, consider a signal with a bandwidth or highest frequency of B = 100 Hz. The sampling theorem states that sampling frequency would have to be greater than 200 Hz. Sampling at 200 Hz would result in β = 1. Sampling at four times that rate (β = 4) would result in a sampling rate of 800 Hz. This gives the anti-aliasing filter a transition band of 600 Hz ( (fs−B) − B = (800 Hz−100 Hz) − 100 Hz = 600 Hz) instead of 0 Hz if the sampling frequency was virtually 200 Hz.
An anti-aliasing filter with a transition band of 600 Hz is much more realizable than that of 0 Hz (which would require a perfect filter). If the sampler went to eight times over then the transition band would increase to 1400 Hz, which means the anti-aliasing filter could be less expensive due to relaxation of the transition band requirements.
After being sampled at 800 Hz, the signal (ostensibly with a bandwidth of 400 Hz) could be digitally filtered to have a bandwidth of 100 Hz and then further downsampled to closer to 200 Hz.
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Dakle, bar kako ja tumačim ovo, oversempling se koristi da bi se nadomestila nesavršenost filtera, kao što i piše u članku, na šta se tačno odnosi primedba za pogrešnu interpretaciju?
Ili li se ovde misli, ako uzmemo taj 44.1 standard, da se oversampling radi na jos vecoj frekvenciji, tipa 88.2, ili 192, a ne da je tih 2.05 (22,050-20000) khz ostavljeno radi toga?