Sampling and the Nyquist rate
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
•Can give you
the wrong signal/image—an alias
•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
•This minimum
sampling rate is called the Nyquist rate
