Accessible math – Foxit is spearheading the implementation of new PDF features

As a leading PDF manufacturer, Foxit is actively working on the realization of new features specified in PDF 2.0. In some cases, multiple stakeholders are needed to make the new functions available to users as a consistent end-to-end solution.

Supporting accessible math via inclusion of MathML in PDF is one such example in which Foxit initiated and actively supported a proof of concept, thus providing the FIRST implementation.

Accessible math is difficult to achieve using PDF 1.7 and PDF/UA-1. In this context, the workaround is an image of the formula described via alternate text. However, this approach only addresses, at best, simple formulas like the Pythagorean theorem or Einstein's famous E=mc². With complex mathematical formulas, navigation within the formula is particularly necessary.

The introduction of PDF 2.0 and PDF/UA-2 introduced better capabilities for math through MathML. MathML (Mathematical Markup Language) is an XML-based markup language specifically designed for mathematical expressions and formulas. In PDF 2.0, MathML may be directly included within a Formula tag, as either marked page content or as an embedded and associated file that contains the formula.

In practice, accessible Math presents a chicken-and-egg problem because several applications must work together in order to offer a consistent end-to-end solution.

Authoring: LaTeX is commonly used to create scientific and technical documents containing formulas, such as mathematical or scientific papers at universities and colleges or in scientific publications or scientific journals.

Conversion: After creation in, e.g., LaTeX, finished content is typically converted to PDF.

Viewing: Users employ a PDF viewer to read or a PDF editor to make further changes.

Assistive Technology: To ensure that publications including MathML are also accessible to people with visually impairments, the use of a screen reader such as NVDA, JAWS or similar technology, is necessary.

Foxit implemented display and editing of MathML in the Foxit PDF Editor and PDF Reader. The Foxit PDDom interface (API), which has been expanded, is available for communication with a screen reader. For this purpose, Foxit worked intensively with an NVDA expert who implemented the necessary functionality. Foxit was able to advice on best practices how to effectively embed MathML into generated PDFs from LaTeX. The results of this proof of concept will now gradually be incorporated into the next releases of LaTeX and NVDA applications.

Foxit is once again a pioneer in making the benefits of PDF 2.0 and PDF/UA-2 available to users.