Quantization (signal processing)

In digital signal processing, quantization is the process of approximating a continuous signal by a set of discrete symbols or integer values. In general, a quantization operator can be represented as

Q(x) = round(f(x))

where x is a real number, Q(x) an integer, and f(x) is an arbitrary real-valued function that controls the 'quantization law' of the particular coder.

For example, in digital telephony, two popular quantization schemes are the 'A-law' and 'µ-law', each mapping an analog signal to an integer value represented by an 8-bit binary number, but each with a different function f.