Digitizing

Digitizing or digitization[1] is representing an object, image, document or a signal (usually an analog signal) by a discrete set of its points or samples. The result is called "digital representation" or, more specifically, a "digital image", for the object, and "digital form", for the signal. McQuail identifies the process of digitalization having immense significance to the computing ideals as it "allows information of all kinds in all formats to be carried with the same efficiency and also intermingled" (2000:28) [2]

Analog signals are continuously variable, both in the number of possible values of the signal at a given time, as well as in the number of points in the signal in a given period of time. However, digital signals are discrete in both of those respects, and so a digitization can only ever be an approximation of the signal it represents.

A digital signal may be represented by a sequence of integers. Digitization is performed by reading an analog signal A, and, at regular time intervals (sampling frequency), representing the value of A at that point by an integer. Each such reading is called a sample.

A series of integers can be transformed back into an analog signal that approximates the original analog signal. Such a transformation is called DA conversion. There are two factors determining how close such an approximation to an analog signal A a digitization D can be, namely the sampling rate and the number of bits used to represent the integers.