Digitizing

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"Digitizer" redirects here. For the computer device, see Digitizing tablet. For the digitizer in Tablet PC's, see Tablet PC.

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.

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.

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[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 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.[citation needed]

"Digitization" is also used to describe the process of populating databases with files or data. While this usage is technically inaccurate, it originates for the previously-proper use of the term to describe the part of the process which involved converting the analog sources (printed pictures, printed brochures, etc.) into the digital representation before uploading to the target database(s).

Digitizing is also used in the field of apparel where an image is recreated by artists with the help of embroidery digitizing software tools and saved as embroidery machine code. This machine code is fed into an embroidery machine and embroidered onto apparels. The most supported format is DST file.

Digitizing also refers to the process of acquiring precise dimensions from a real world object, such as a car, using a CMM (Computer-Aided Manufacturing Measurement) device.[1]

[edit] Analog signals to digital

Nearly all recorded music has been digitized. About 12 percent of the 500,000+ movies listed on the Internet Movie Database are digitized on DVD.

[edit] Analog texts to digital

About 5 percent of texts have been digitized as of 2006.[2]

Older print books are being scanned and optical character recognition technologies applied by academic and public libraries, foundations, and private companies like Google.[3]

Unpublished text documents on paper which have some enduring historical or research value are being digitized by libraries and archives, though frequently at a much slower rate than for books (see digital libraries). In many cases, archives have replaced microfilming with digitization as a means of preserving and providing access to unique documents.

[edit] Collaborative digitization projects

There are many collaborative digitization projects throughout the United States. Two of the earliest projects were the Collaborative Digitization Project in Colorado and NC ECHO - North Carolina Exploring Cultural Heritage Online, based at the State Library of North Carolina. These projects establish and publish best practices for digitization and work with regional partners to digitize cultural heritage materials.

[edit] Library Preservation

Digital preservation at its most basic definition is a series of activities aimed towards ensuring access to digital materials over time.[4] Digitization is a means of creating digital surrogates of analog materials such as books, newspapers, microfilm, and videotapes. Digitization can provide a means of preserving the content of the materials by creating an accessible facsimile of the object in order to put less strain on already fragile originals.

The prevalent Brittle Books[5] issue facing libraries across the world is looking towards a digital solution in long term preservation.[6] For centuries, books were printed on wood-pulp paper, which turns acidic over the period of its decay. As the paper ages, it deteriorates to a point of being completely unusable. In theory, if these widely circulated titles are not treated with de-acidification processes, the materials upon those acid pages will be lost forever. As technology evolves, it is increasingly becoming a preferred method of preserving these materials - maily because it can provide easier access points and significantly reduced amounts of physical storage space.

Google, Inc. has taken steps towards attempting to digitize every title with "Google Book Search"[7][8]. While some academic libraries are in contract with the service, issues of copyright law violations threaten to derail the project.[9] However, it does provide - at the very least - an online consortium for libraries to exchange information and for researchers to search for titles as well as review the materials.


[edit] Fiction

Works of science-fiction 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). In the video game Beyond Good and Evil the protagonists holographic friend digitizes the players inventory items.

[edit] See also

Look up digitizing, digitisation in Wiktionary, the free dictionary.

[edit] References

  1. ^ http://www.digimation.com/home/?Content=digitalcarshome.html
  2. ^ New York Times; May 14, 2006; Scan This Book!
  3. ^ http://www.google.com/press/pressrel/print_library.html "Google Checks Out Library Books," Press release, December 14, 2004
  4. ^ “What is Digital Preservation”. Library Technology Reports 44:2 (Feb/March 2008).
  5. ^ http://en.wikipedia.org/wiki/Brittle_Books_Program
  6. ^ Cloonan, M.V. and Sanett, S. “The Preservation of Digital Content,” Libraries and the Academy. Vol. 5, No. 2 (2005): 213-37.
  7. ^ http://en.wikipedia.org/wiki/Google_Book_Search
  8. ^ http://books.google.com/
  9. ^ Baksik, C. “Fair Use or Explotation? The Google Book Search Controversy,” Libraries and the Academy. Vol. 6, No. 2 (2006): 399-415.