A document reader is a device that converts an electronic file or printed matter to a form suitable for use by people with visual impairment. The output can be in the form of enhanced video, speech, or Braille.
Some document readers act like zoom viewers; they make characters on a computer screen look larger. These devices are suitable for people with some visual impairment (such as macular degeneration) but not total loss of vision. For people lacking sight entirely, there are document readers that can transcribe electronic files, such as Web pages, rendering output in speech or Braille. Other devices are designed to transcribe printed matter into speech or Braille.
A document reader for printed matter consists of a scanner , an optical character recognition ( OCR ) program, and a speech synthesizer or Braille display . When printed matter is scanned, the OCR program converts the text into an ASCII file (plain digital text). A speech synthesizer converts the ASCII into audible words and sentences. A Braille display produces elevated dots on a surface, allowing the user to read the document as if it is a book or magazine page in Braille. The Braille version can be used by people who are deaf as well as blind.
Computer programs for displaying text and graphics documents in specific formats, such as Adobe's Portable Document Format ( PDF ), are sometimes called document readers.