REPRESENTING AND DISPLAYING BRAILLE

What is a braille equivalent?

A braille equivalent is an alternate form of a braille transcription that could be used as a valid source or basis for proofreading. There are two types of braille equivalents. The standard type of equivalent is a one-for-one or direct substitution like Braille ASCII or the braille analogs. A direct equivalent just uses 63 different characters or numerical codes for the 63 different braille cells. The other type of braille equivalent is many-for-one; several different characters or numerical codes are used for each braille cell depending on context. Of course, a many-for-one equivalent is only valid if it can be automatically reduced to a direct equivalent using simple character substitution without any additional translation. (The reverse process--producing a useful many-for-one equivalent--is, of course, less straightforward.)

A many-for-one braille equivalent, like DotlessBraille™, has the advantage is that it can be displayed in a manner that is simpler for sighted persons to read since it is more like ordinary printed material, which doesn't make as much use of context as braille does. Any display of a braille equivalent for proofreading purposes also requires use of the same layout as the corresponding braille. This is done in DotlessBraille displays by using one fixed-width print character for one braille cell. See also our proposed method for generating the many-for-one braille equivalent source for this type of display that would only require minor conceptual changes to current computer-based transcribing methodology.

What is Braille ASCII?

Braille ASCII is a one-to-one braille equivalent that maps the braille cells plus the space character to the set of 64 ASCII (American Standard Code for Information Interchange) character codes in the range 32-95. Braille ASCII is currently the main method for specifying braille cells in an electronic file since most embossers are set up to use it. (The newer Unicode character codes for the Braille Patterns are not yet widely used.)

All of the ASCII codes used in Braille ASCII are part of the subset of the ASCII code that corresponds to standard keyboard characters but these keyboard characters are not necessarily related to the meanings of the braille cells in any particular braille code. Braille ASCII was designed for the purpose of communication between early electronic devices that recognized the ASCII characters and not particularly for use by humans.

Since Braille ASCII is a braille equivalent, it is possible to use the equivalent keyboard characters for debugging transcription applications. However, the illogical and inconsistent relationship between these characters and even the default meanings of the cells according to either the literary braille code or the Nemeth code, let alone any other braille code, make it inappropriate for general proofreading. (For example, an exclamation point keystroke corresponds to the dot pattern for "the" in literary braille while the numeral six corresponds to the dot pattern for a literary braille exclamation point.) Moreover, Braille ASCII is not a braille analog so additional information is needed to determine the dot patterns.

The chart shows each of the 63 Braille ASCII codes displayed as their equivalent keyboard character with the primary meaning of the referenced braille cell

    
     A  B  C  D  E     F  G  H  I  J
     a  b  c  d  e     f  g  h  i  j

     K  L  M  N  O     P  Q  R  S  T
     k  l  m  n  o     p  q  r  s  t

     U  V  X  Y  Z     &   =  (   !    )
     u  v  x  y  z    and for of the with 

     *  <  %  ?  :     $  ]  \  [  w
     ch gh sh th wh    ed er ou ow w

     1  2  3  4  5     6  7  8  9  0
     ,  ;  :  .  en    !  (  ?  in "

     /   +  #  >  '  -
     st ing #  ar '  - 

     @  ^  _  "  .  ;  , 
     ‘  03 07 02 05 06 04

Chart. Braille ASCII with literary braille.
according to the literary braille code shown underneath; note that the Braille ASCII use of the ASCII numerals for the lower-cell signs is the
Nemeth convention for numerals rather than the literary use of these cells for punctuation marks. (The literary braille indicators in the last row of the chart are labeled here with their NUMBRL codes since they have such a variety of different meanings in different contexts.)

This chart is arranged according to the so-called standard display which emphasizes the row-to-row similarities in the dot patterns. The same set of dot patterns is used for the upper part of the corresponding cells in each of the first four rows: the second row adds a dot in position 3, the third row in positions 3 and 6 and the fourth row in position 6. The fifth row is the lower-cell version of the first row. The sixth row has the remaining dot patterns that make use of dot position 3 in the left-hand column plus various dot patterns for the right-hand column. The last row has the seven dot patterns that have filled positions only in the right-hand column. (The last two rows correspond to row 40--with the omission of dot patterns 3-5 and 3-5-6--and row 00, respectively, in the Find-A-Cell Chart).

Most computer-based transcribing systems transcribe a print source--in the form of an electronic file--into Braille ASCII, which is then used as input for rendering by a refreshable braille display so the transcription can be proofread by blind persons who have been certified by the Library of Congress (LOC) as braille proofreaders. (There is no legal reason why sighted persons cannot be braille proofreaders; however, in practice only one or two are currently certified in this capacity.) Proofing can also be done using an embossed version of braille but indicating errors is more difficult; the LOC does not require that a transcription be proofed using an embossed display.

What is a braille analog?

A braille analog is any method of encoding the dot patterns of the braille cells--other than simulated braille--that allows the patterns to be reconstructed by decoding the analog according to a key. Analogs may be decoded either visually or mathematically. Different forms of Braille analogs are useful for different purposes.

What is simulated braille?

Simulated braille is another name for inkprint fonts that use dots to display the braille cells. Most of the print dots here use the Duxbury Systems, Inc. SimBraille© font. This font is an example of grid braille which includes shadow dots in unfilled positions. Anther way of representing the dot patterns in inkprint is to use one of the braille analogs.

Dotless Braille Tip! SimBraille uses Braille ASCII as its keyboard mapping. This means that if you type the Braille ASCII characters and change the font to SimBraille, you will get the corresponding cells. If you have one of the Duxbury fonts installed, you will see this here; if not, you'll just get Braille ASCII. abcde uvxyz

However, these keystrokes are hard to remember. You can remap your keyboard with a shareware program like KickKeysLite©. Read here how KickKeys works.

What is Dotless Braille?

Dotless Braille is an idea for a new way of presenting a braille transcription in a dot-free equivalent form for sighted persons; this display method is valid for proofreading computer-generated braille transcriptions. (DotlessBraille™ displays are currently created by hand; however, one of the purposes of this website is to generate interest in automating this process.)

The unusual aspect of the display is that each braille cell in a braille transcription is displayed in DotlessBraille™ as part of a semantically correct fixed-width print character that encapsulates both the local or context-dependent meaning of the braille cell as well as any typesetting necessary to show the effect of embedded markup characters. A one-for-one display is, of course, essential for proofreading. The display of the logo at the top of our home page is an example of DotlessBraille™ display.

I should point out that a braillist has objected to my use of the word braille since, by using more that 63 characters and various print styles, Dotless Braille violates the spirit of braille by obviating the need to consider context in order to determine meaning. However, this is to some extent the same as saying that a person who only knows eight-dot braille doesn't know braille.

It is certainly true that a person whose only familiarity is with a many-to-one braille equivalent such as Dotless Braille will not have acquired the skills to read a one-for-one six-dot braille equivalent such as braille ASCII or simulated braille. Nonetheless, it is possible to develop rules for proofreading Dotless Braille that are sufficient to ensure that the underlying braille is correct and some individuals whose only braille goal is to be able to function as a proofreader should find this approach easier.

Hopefully this idea can be made clear by the following example. Imagine that there are at most four different meanings for any one braille cell. Also, consider a new form of eight-dot braille in which the first six dots are the same as ordinary six-dot braille but dots seven and eight are used to distinguish among the different meanings for a given cell. For example, (dots 256) used as a period might not use any additional dots while the same cell used as dd might add dot 7. In Dotless Braille displays, the use of additional characters and typesetting play the same role as would the use of the extra dot positions.

This page was last updated on February 20, 2002.