Aliasing in sampling

Aliasing is the effect of new frequencies appearing in the sampled signal after reconstruction, that were not present in the original signal. It is caused by too low sample rate for sampling a particular signal or too high frequencies present in the signal for a particular sample rate.

1. What is aliasing and how it is reduced?
2. What is meant by the term aliasing?
3. What is aliasing in Nyquist?
4. What is aliasing and types of it?

What is aliasing and how it is reduced?

Aliasing is characterized by the altering of output compared to the original signal because resampling or interpolation resulted in a lower resolution in images, a slower frame rate in terms of video or a lower wave resolution in audio. Anti-aliasing filters can be used to correct this problem.

What is meant by the term aliasing?

ali·​as·​ing ˈā-lē-ə-siŋ ˈāl-yə- : an error or distortion created in a digital image that usually appears as a jagged outline. We commonly observe aliasing on television.

What is aliasing in Nyquist?

When a component of the signal is above the Nyquist, a sampling error occurs that is called aliasing. Aliasing “names” a frequency above Nyquist by an “alias” the same distance below Nyquist. Sinusoidal signal at 1.3 times Nyquist before sampling into pixels.

What is aliasing and types of it?

Aliasing is the visual stair-stepping of edges that occurs in an image when the resolution is too low. Anti-aliasing is the smoothing of jagged edges in digital images by averaging the colors of the pixels at a boundary. The letter on the left is aliased.