## Converters

In the last twenty years, various projects have been developed with the aim of facilitating the written communication between sighted persons and Braille readers in the ﬁeld of Mathematics. Converters, that allow to performs conversions between mainstream mathematical formats like LATEX and MathML and Braille notations, are used for different purposes.

One is to facilitate the production of Scientific documents in Braille. Indeed it is much easier to produce a document containing Mathematical expressions in LATEX or to use a word processor that supports MathML than to write a document in Mathematical Braille. Additionally a lot of resources are available in these both formats.

In the other way (from Braille notations to mainstream formats) they allow sighted teachers or peers to access to formulas written by blind students.

### LaTeX to Braille

#### Labradoor

Labradoor (LAtex to BRAille DOOR) converts a full LATEX document including Mathematical formulas into Marburg Braille or into HRTeX (Human Readable Tex). In addition, it offers a rich variety of formatting capabilities, enabling the production of Braille hard copies out of formatted LATEX documents.

- Batusic, M., Miesenberger, K., and Stöger, B. (1998).
*Labradoor, a contribution to making mathematics accessible for the blind*. In Edwards, A., Arato, A., and Zagler, W., editors, Proc. ICCHP 98 (6th International Conference on Computers Helping People with Special Needs), Oldenbourg, Wien, München.

### MathML to Braille

Various converters from MathML to Braille have been recently developed. They allow transcribers to design Mathematical content using mainstream Maths editors.

#### Bramanet

Bramanet converts formulas from MathML to French Braille. It is an application based on the XSLT technology. It allows various settings including the possibility to edit the output Braille table in order to ﬁt with any hardware. It comes with a script which makes automatically a conversion from a document containing Maths formulas to a document ready to be embossed in Braille.

#### math2braille

math2braille is a “self-contained Module” which takes in a MathML ﬁle and outputs a Braille representation of the same Maths. It is based on protocols and procedures that have been developed in a previous project about access to music. It produces Braille code in use in the Netherlands.

#### Nemeths conversion

Paul Stanley developed a translator from MathML to Nemeth Braille Code. The translation is performed in 2 phases. First the MathML elements are translated to Nemeth codes. Then syntactic rules that are inherent to Nemeth code are applied, such as the use of the numeric indicator, additional spaces, and some contractions. These rules were fashioned by Dr Nemeth to direct the conversion of Mathematics into the Braille code.

*Translating mathml into nemeth braille code*, by P. Stanley and A. Karshmer. In K. Miesenberger, J. Klaus, W. Zagler and A. Karshmer editors, Proc. ICCHP 2006 (10th International Conference on Computers Helping People with Special Needs), volume 4061 of LNCS, pages 1175–1182, Linz, Austria. Springer.

### From Braille to mainstream

#### Insight

Insight proposes a complete system to translate Maths documents with mixed Grade II Braille text and Nemeth code to LATEX. The back-translator is based on language semantics and logic programming. The system processes an image of a Braille sheet (for instance a scanned page) and recognises the Braille dots to produce an ASCII Braille ﬁle. Text and Nemeth code are automatically identified and separated to be separately translated. Finally a single LATEX document is produced to be read by a sighted individual. It is distributed by Logisoft Solutions LLC under the name *TransBraille*.

### Miscelaneous

#### Infty

Infty is a large pro ject aiming at giving access to printed mathematical content. It is base on a core module (InftyReader) which is an OCR specialised in Mathematical documents. It is able to extract mathematical formulas in a scanned document and to recognise the mathematical structure and the symbols. It produces a topological representation of the formulas in an XML format. Then this representation can be converted into various formats: MathML, LATEX, HTML, HRTeX, KAMS, and into Uniﬁed Braille Code (English) and Japanese Braille code.

Some additional tools have been developed by the same group, in order to extend the possibility of the system. InftyEditor allows to edit the output of InftyReader. It proposes also a handwriting dialog in which users can write formulas by hand, to be recognised automatically. ChattyInfty is adding speech output to the system. It allows visually impaired users to access expressions with speech output but also to author and edit them.