Digitizing

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Digitizing or digitization is representing an object, an image, 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.

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. The digital representation does not necessarily lose information from this transformation since the analog signal usually contains both information and noise.

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.

1 Usage examples
2 Analog to digital
3 Fiction
4 See also
5 References

[edit] Usage examples

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 dots 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.^{[citation needed]}

[edit] Analog to digital

Nearly all recorded music has been digitized. About 10 percent of the 500,000 or so movies listed on the Internet Movie Database are digitized on DVD. About 5 percent of texts have been digitalized as of 2006. ^[1]

[edit] Fiction

Works of science-ficton often include the term digitize as the act of transforming people into digital signals and sending them into a computer. When that happens, the people disappear from the real world and appear in a computer world (as featured in the cult film Tron or the animated series Code: Lyoko).