Digitizing or digitization 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)

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.

Usage examples

The term digitization is often used when diverse forms of information, including text, sound, image and voice, are encoded in a single 0-1 binary code. Digital information exists in only one of two forms -0 or 1- which are called bits (a contraction of 'binary digits'), and the sequences of 0s and 1s that constitute information are called bytes.

The term is often used for the scanning of analog sources, such as printed photos or taped videos into computers for editing, but it also can refer to audio (where sampling rate is often measured in kilohertz) and textures map transformation. In this last case, as in normal photos, sampling rate refers to the resolution of the image (often measured in pixel per inch). Digitizing is the primary way of storing images in a form suitable for transmission and computer processing.

Digitizing is making a digital representation of geographical features within a raster image or vector using a geographic information system, i.e, the creation of electronic maps, either from various geographical imagery or by digitizing the traditional paper maps.

Since the advent of digital video the term continues to be frequently used, as of 2005, to refer to the process of importing footage into a computer via a FireWire cable. But this is not technically accurate, as the footage is already digital, so it is not really being digitized, but rather encoded into whatever format the non-linear video editing software uses. Fact: date=February 2007