Digital Cinematography, 2nd Edition

Understanding Digital Theory 11

Figure 1.23 Reconstruction from too few samples

fails to reconstruct.

When even fewer samples are taken from the

original waveform, the digital reconstruction

does not resemble the original wave form in any

way. This reconstruction is said to be an “alias”

of the original waveform.

Nyquist Shannon Sampling Theory

To accurately reconstruct the analog wave forms

that form the original picture signal the sampling

rate must be more than twice the highest fre-

quency contained in those analog signals.

3

If the frequency of analog wave forms is sam-

pled at less than two times the highest frequency ...