Digitizing
Digitizing, or
digitization, is the process of turning an
analog signal into a rough
digital representation of that signal. The term is often used for the scanning of analog
photos and
video into computers for editing, but it also can refer
audio (where sampling rate is often measured in
kilohertzs) and textures map transformation. In this last case, like in normal photos, sampling rate refers to the
resolution of the image (often measured in
dots per inch).
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.
A digital signal consists of a sequence of integers, each integer often represented by a binary number. 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 is not an approximation to an analog signal. However, a series of integers can be transformed 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.
The images we see on the TV screen, the
raster display of a computer, or in newspapers are in fact "digitized images".
Digitizing is the primary way of storing images in a form suitable for
transmission and
computer processing.
The term
digitizing is also used to describe the process of making a digital representation of features within a raster image using a
geographic information system.
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.
Sci-fi comics often include the term
digitize as the act of transforming people into digital signals, sending them to a computer. When that happens, the people disappear from real world and may appear in a
virtual reality game.
This is not the same as the act to get the texture of a real object and digitizing it â€" this is very common in modern
films and
video games, such as
Mortal Kombat.
Digitize can also be used as the act of converting a surface position into digital coordinates
data.
*
Analog to digital converter*
Digital audio*
Graphics tablet*
Pattern digitizing*
Raster image*
Raster graphics*
Raster to vector*
Rotoscope*
Vector graphics
