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Extended Braille and DotlessBraille

ASCII Braille

The standard way of representing braille cells electronically uses 63 ASCII character codes for the 63 braille cells. There is also a Unicode prescription but I'm not aware of any braille applications that make use of it.

An Advantage of ASCII Braille Over Unicode

One advantage of ASCII Braille—actually a consequence of its violation of the Unicode philosophy of unique character codes for unique characters and symbols—is that sighted persons can choose to read ASCII Braille either as plain text or as inkprint braille dots simply by changing the font.

For example, the term DotlessBraille is written in contracted braille using the cells:
,DOT.S,BRL
with the ASCII Braille displayed as plain text. If you have either CAI's BRL2000 font or Duxbury's SimBraille font installed, then the next line will display the corresponding inkprint dots:
,DOT.S,BRL
simply as a result of the change in the font specification.

Some Disadvantages of ASCII Braille

ASCII Braille also has a number of disadvantages. In the first place, it takes quite a while for a sighted person to become adept at reading braille files as either plain text or inkprint dots. Consider, for example, the simple sentence, "Can you read this?"

When this sentence is transcribed to contracted braille, the word can is represented by the single-letter contraction "c", the word you by the single-letter contraction "y", the "ea" by the single cell for the "ea" contraction, and the word this by the single cell for the "th" contraction. And just to make things even more confusing, ASCII Braille represents the capitalization indicator with a comma, the "ea" contraction with the digit 1, the "th" contraction with a question mark, and the question mark with the digit 6.
,C Y R1D ?6

ASCII braille also causes difficulties for machine processing because the determination of the local meaning of the braille cells requires consideration of context.

Extended Braille

Extended braille, in contrast to ASCII Braille and other standard digital representations of braille, uses separate character codes for each different meaning of the braille cells rather than for each different cell. Extended braille for Grade 2 braille has approximately 500 character codes rather than only 63.

An Advantage of Extended Braille Over ASCII Braille

Extended braille supports a directly readable print-like display by using the DotlessBraille font, a new font that has different glyphs for each different extended braille character code. (There is a companion font called XBraille which can be used for displaying extended braille as standard inkprint dots.) The DotlessBraille and XBraille fonts were recently created by an extremely talented and generous volunteer.

Here is the extended braille representation of the phrase "DotlessBraille" with the extra characters that don't appear on a standard keyboard represented with numeric character references:
ȠdotīĬȠƩƪƫ

Since the two fonts based on extended braille are not currently available for distribution, I've included a description as well as a picture of the previous two lines as they appear when displayed using the DotlessBraille and XBraille fonts. (The picture was obtained by scanning a printout of the appropriate selection from an earlier version of this page as displayed on my PC with the fonts installed.) I left the HTML here for future reference even though I of course realize that without the new fonts the line will not display correctly but will have funny characters and/or boxes for "missing characters".

Description of DotlessBraille and XBraille Sample

DotlessBraille is a fixed-width font that can be aligned exactly with the XBraille companion font which displays the corresponding inkprint dots. In the sample picture each XBraille glyph appears directly below the corresponding DotlessBraille one.

• The DotlessBraille glyph for the capitalization indicator is an upward pointing outline of an arrow surrounded by a rectangle; the arrow is similar to the one typically printed on the Shift key on a standard keyboard.
• The glyphs for letters are standard fixed-width lowercase print letters.
• The glyphs for contractions and short-forms are lowercase letters squashed together to take up the same space as the corresponding number of braille cells. The two-cell initial-letter contraction for "less" requires two glyphs: the first glyph is the first two letters squashed together and the second is the last two letters. The three-cell short-form for "braille" requires three glyphs: the first two each have two letters squashed together and the last one has three.

Summary

Extended braille and the DotlessBraille font have the potential to revolutionize braille transcribing by making electronic braille directly accessible to sighted persons.

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Page History:

• First posted August 13, 2003
• Revised August 15, 2003
• Revised September 5, 2003