Highly Accessible Scientific Graphical Information through DAISY SVG

John Gardner
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The DAISY (Digital Accessible Information SYstem, www.daisy.org) organization has developed an XML specification designed for excellent accessibility of a wide range of written literature. Math is included in the form of the math markup language MathML. DAISY uses SVG as the markup language of choice for accessible graphics. A DAISY SVG Working Group is developing authoring guidelines and expanding SVG to permit excellent accessibility to graphics by people who are blind, dyslexic, or have other severe print disabilities. This talk will discuss these developments from the point of view of an end user.


DAISY is an international consortium of libraries and other organizations serving needs of blind and dyslexic people. ViewPlus is a commercial Friend of DAISY and a leading presence on the DAISY SVG working group. ViewPlus’ "Hands-On Learning" IVEO technology (http://www.viewplus.com/solutions/touch-audio-learning/) is being expanded to develop authoring end user access tools encompassing the DAISY developments.

The American Physical Society (APS), the world’s leading publisher of physics journals, is a DAISY Friend and a member of the DAISY SVG Working Group. APS is developing infrastructure to permit it to begin publishing its journals in DAISY XML.[1] Transforming the current APS XML, which includes math as MathML, into this DAISY format is straightforward, but making its graphics accessible as DAISY SVG is not. APS presently accepts figures in Encapsulated PostScript (EPS) format. APS, ViewPlus, and other organizations are collaborating to develop software that can convert EPS automatically to DAISY SVG. The APS publication project is in practice the test procedure to assure that the DAISY SVG specifications are practical and robust and that they meet the needs of mainstream users as well as users with disabilities.

Basic SVG 1.0 and 2.0 include two features, title and description properties for graphical objects, intended to promote accessibility. ViewPlus has exploited these two fields in its IVEO technology to permit SVG images to be accessible to blind readers. Its IVEO Viewer is used along with a tactile copy of the image to allow "Audio-Touch" access to graphical information. The blind reader typically has a tactile copy (made by printing from IVEO Viewer to a ViewPlus embosser) mounted on a touchpad

When a text span or graphical object is tapped, it is selected and the text span or object title respectively is spoken by the computer. An object description is spoken by double tapping the object.

The IVEO Creator software permits graphic object titles and descriptions to be created and inserted into SVG files. It also has editing capabilities for improving the SVG text information to be most useful to the end user. Typically most graphical authoring applications do not export text in semantically meaningful spans, so the end user will have difficulty understanding text labels on "as-exported" graphics. Assuring that text labels are semantically meaningful and that important graphical objects have titles and, if necessary, descriptions, can make most graphical information equally accessible to people with and without print disabilities. Some graphics, in particular scientific graphics, are not equally accessible with these simple enhancements however. Equations appearing in text labels often cannot be coded in SVG. Even if they could be, speech engines cannot transform such coded equations into understandable speech.

DAISY SVG is being expanded to include a number of tag and attributes to ensure equal accessibility to scientific graphics, in fact to make them even more accessible to all users whether print disabled or not. A number of data-containing fields are being added so that figures can be their own data archives. Including the data in figures as well as images of the data makes those images far more accessible to everybody. Such smart figures have been a dream of foresighted scientists for decades. It is ironic that this dream is reaching reality through a project originally begun to serve needs of blind people. Smart figures will become a practical reality in a few years after authoring applications develop "save-as" capabilities that will automatically include data, titles of data collections, descriptions of fitting curves, etc. Initial APS journals will have no data and will not include titles and descriptions of graphical objects in SVG, but they will have MathML associated with equations. Full accessibility of scientific labels makes many physics graphics moderately accessible, but some editing by sighted associates will still be needed for many images. However the human effort to make articles accessible is minimal compared to the extraordinarily high cost in time and labor of "making scientific information accessible" today.


1. Making journals accessible to the visually impaired: the future is near. John A. Gardner, Vladimir Bulatov, and Robert A. Kelly. Learned Publishing 22(4) 2009 pp. 314-319. http://www.viewplus.com/about/abstracts/09learnpubgardner.html