Aliasing and Nyquist - Introduction & Examples

Показать описание

Рекомендации по теме

Комментарии

1:20 cracked me up! A real example through audio lmao!
The content creator must have a good sense of humor!

rafatulhauque

Very good video. It's a lot of info at first, but after re-watching, it really starts to sink in. Thank you!

RenKohana

Why do people keep saying the Nyquist theorem allows the sampling rate to be *atleast* twice the highest frequency? Exactly twice the highest frequency would represent that highest frequency as a 0 on the y axis. It needs to be *more* than twice the highest frequency for the signal to be represented perfectly.

pasijutaulietuviuesas

Awesome visual aids, I wish the textbook I'm reading used these

LucasAndrewSchweers

the propellor warping is a consequence of rolling shutter effect. Not directly because of aliasing

anomalyp

Aliasing doesn't cause digital images to look blurry. It causes them to look jagged. In the example with the blurry text, that is actually where anti-aliasing has been applied. The blurring is intentional to avoid the jaggedness, and although it looks blurry when zoomed in, it looks better than aliasing when zoomed out.

stephenrobertson

Good video! Helps me understand the criterion well :)

tymothylim

#sampling theorem is divided into two three types they are oversampling, Nyquist and undersampling. #nyquist sampling means perfect sampling ie fs=2fm. #undersampling means sample rate is below the perfect sample rate ie fs <2fm, aliasing effect is used in undersampling.

shruthi

I disagree in what may seem a subtle way. If you capture a signal with a sample rate exactly twice the signal frequency, it aliases to anything from the full amplitude to zero output, depending entirely on where in the phase of the signal the captured samples are taken.

But this also means that if your capture rate is, say, 10Hz above that of the signal frequency, you will have a pulsing as the location of the captured samples changes on the waveform, creating a beat frequency of 10Hz in the sampled waveform.

I welcome corrections.

AlienRelics

Aliasing happens with my eyes sometimes when i look at carwheels? Do we have fps in our eyes

Winsky

It is wrong F_sampling should be > 2F_signal. In the video they have written >=.

afshink

Let's use DA-AD conversion for re-sampling to keep steepness origin. Comparator operational amplifier can do it. Math-algorithmical ones(interpolation, LPF) creates global nonsenses even in audio. There is a many records, especially in movies, that combine 44100Hz music with 48k-192k sounds and dialogs. And its bad, when they using virtually re-computed signals in mixture. Class-A signal processing is the only way.

jirioto