Aliasing
can arise when you sample a continuous signal or image
•occurs when your sampling rate is not high enough to capture the
amount of detail in your image
•formally,
the image contains structure at different scales
–called
“frequencies” in the Fourier domain
•the
sampling rate must be high enough to capture the highest frequency
in the image
To avoid aliasing:
•sampling
rate > 2 * max frequency in the image
–i.e.,
need more than two samples per period
•This
minimum sampling rate is called the Nyquist rate