Video signal digitization
Digital video signal

Digitizing any signal involves first – and then, after filtering to avoid spectrum aliasing –, sampling it.

These analog samples are then quantized on a number of levels, giving a parallel n-bit bitstream. For ease of transport, this is followed by a serialization step, enabling us to return to coaxial cable as in analog.

Digitizing a video signal imposes additional constraints due to its three-dimensional aspect. The signal must be sampled and quantified, and a sampling structure chosen that takes into account both the spatial and temporal aspects of the image.

Let's recall some of the characteristics of the video signal. We live in a four-dimensional space, with three spatial dimensions and one temporal dimension. With the advent of television, one spatial dimension disappeared, as the camera lens projects reality onto a plane. All that remains are two spatial dimensions (horizontal...