14 - Anti-aliasing

Question 1

What Causes Aliasing?

Answer 1

Signal contains half of the sampling frequency ( Nyquist frequency)

when the sampling rate or resolution is not high enough to accurately represent a continuous signal or image.

undersampling is what causes aliasing; this is where not enough discrete samples are taken to capture a fast rate of change.

Question 2

Antialiasing

Answer 2

Techniques to avoid aliasing.
Lowpass filtering on an image has to be simulated.

Question 3

Low pass frequency

Answer 3

Attenuation of high frequency components of a signal while preserving low frequency signals

Question 4

Antialiasing can be

Answer 4

• no filtering
• pre filtering - before signal is sampled (simulation)
• post filtering ( approximation)