Braille

From ArticleWorld

The braille system, named after its inventor, Louis Braille, is a special alphabet used by blind people to read and write. Each character in the braille alphabet consists of a number of dots on two columns, forming a total of 64 combinations.

Historically, the system originated when Napoleon wanted a system that would allow soldiers to communicate at night, without light or noise. Charles Barbier elaborated one, but it was too complex to be learned. In 1821, Louis Braille restructured it so that the human fingers could read a whole character without moving.

The alphabet

The Braille system is remarkable for being the first binary character encoding. It is not just a character encoding that maps characters of the French language to tuples, it is a set of six-bit characters.

Today, various Braille encodings exist, not just for different character sets of various languages, but also for mathematics or music.

A cell represents a character by using six dots on two columns of three, risen or not. The Braille character set originally described by Braille uses the top 4 dots for letters 'a' to 'j'. The bottom dots are used to letters from 'a' to 'e' to form the other letters, except for 'w', which wasn't in the French alphabet at the time and wasn't, therefore, encoded. Similar standards exist for punctuation, but the limitations of the set cause numbers and capital letters to be denoted using a prefix.

Writing braille is done using a slate and a stylus, but may also be done using a special braille typewriter or a braille embosser and a computer. The computer may also allow braille texts to be rendered on a refreshable braille display.

Transcription

Special methods of transcription exist, as the braille characters are bigger than their usual equivalents, making them more difficult to print. The Grade 2 Braille includes a number of standards, like contracting the word "but" in the single letter "b". This is done in order to allow faster reading and require less space for braille texts.