Digitizing, or digitization, is the process of turning an analog signal into a digital representation of that signal. 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. But the digital representation does not necessarily lose information since the analog signal usually contains both information and noise. For the Analog Science Fiction and Science Fact publication, see Astounding Magazine. ... A digital system is one that uses discrete values rather than a continuous spectrum of values: compare analog. ... In mathematics, a group representation is a way of viewing a group in some more concrete way. ... In mathematics, a continuous function is one in which arbitrarily small changes in the input produce arbitrarily small changes in the output. ... 8:17 am, August 6, 1945, Japanese time. ... The word discrete comes from the Latin word discretus which means separate. ... An approximation is an inexact representation of something that is still close enough to be useful. ...

A digital signal consists of a sequence of values, each value often represented by a sequence of bits, and each bit often represented by a voltage level. 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 a digital value. Each such reading is called a sample. A bit (abbreviated b) is the most basic information unit used in computing and information theory. ... In the physical sciences, potential difference is the difference in potential between two points in a conservative vector field. ... The sampling frequency or sampling rate defines the number of samples per second taken from a continuous signal to make a discrete signal. ... A sample refers to a value or set of values at a point in time and/or space. ...

There are two main factors determining how close an approximation to an analog signal A a digitization D can be. The bit rate of D, formally the number of bits in D per time unit, represents how often A is sampled. In telecommunications and computing, bit rate (sometimes written bitrate) is the frequency at which bits are passing a given (physical or metaphorical) point. It is quantified using the bit per second (bit/s) unit. ...

The images we see on the TV screen, the raster display of a computer, or in newspapers are in fact "digitized images". Suppose the smiley face in the top left corner is an RGB bitmap image. ...

Digitizing is the primary way of storing images in a form suitable for transmission and computer processing. In communications, transmission is the act of transmitting electrical messages (and the associated phenonomena of radiant energy that pass through media). ... A computer is a device or machine for making calculations or controlling operations that are expressible in numerical or logical terms. ...

See also

• Analog to digital converter
• raster image
• raster graphics
• vector graphics
• digital audio