EE4209/EE5809 Sampling and Aliasing

EE4209/EE5809 Sampling and Aliasing

1. The sample areas are designated by rectangles which we call sample blocks.

2. under-sampling : your sampling rate did not keep up with the rate of change of the pattern in the image.

3. With regard to sampling rate, Hz means samples per second, with regard to a sound wave, Hz means cycles per second.)

4. Nyquist theorem, which specifies the sampling rate needed for a given spatial or temporal frequency.

5. Nyquist theorem states that to guarantee that no aliasing will occur, you must use a sampling rate that is greater than TWICE the frequency of the signal being sampled.

6. Let f be the frequency of a sine wave. Let r be the minimum sampling rate that can be used in the digitization process such that the resulting digitized wave is not aliased.

Then r = 2f, r is called the Nyquist frequency.