SVG Mapping for People with Visual Impairment

SVGOPEN Conference 2003 - Vancouver - Canada

Authors

Benjamin Campin (DBx Geomatics), bc@dbxgeomatics.com
William McCurdy (One world Solution), wamccurdy@rogers.com
Louis Brunet (Motus Creative), motuscreative@sympatico.ca
Eva Siekierska, (Natural Resources Canada) siekiers@nrcan.gc.ca
     

Abstract

Introduction

For vision impaired persons getting something as simple as a map of the city they live in can be a big challenge. Improvements in technology and reduction in costs now make it possible to produce tactile maps economically. Web-related technologies are emerging that make map-based information accessible online for those who need it most.

The flexibility of the SVG format and the interactive features of the maps created with it, really enhance the user experience. For the blind user, tactile, audio, and haptic effects convey the information that a sighted person would receive visually.

During this project we created visually simple maps. But we have found that uncluttered maps can still be packed with information. The reduction in visual complexity is compensated by an increase of information conveyed by audio or haptic means.

The current and potential use for these Maps are education, mobility, transportation and tourism. Audio maps could be also useful to sighted people.

Background Information

In 1998, the Mapping and Services Branch of Natural Resources Canada initiated a tactile mapping program to serve the community with special needs, namely the blind and vision impaired. The initiation of this program was part of an international project by the Pan American Institute of Geography and History (PAIGH) on Geographical Information Processing and Electronic Atlases for sustainable development in Latin America. One of the components of the project was the production of Telala (Tactile Electronic Atlas of Latin America). Natural Resources Canada produced a Tactile Atlas of Canada in both English and French. This was followed in 2002, with the launch of the Tactile Maps of Canada web site. http://www.tactile.nrcan.gc.ca/

Tactile Maps

Several technologies exist that produce tactile maps. We produce ours by passing a printed map through a thermal enhancer. The heat raises the ink, creating a map that vision impaired people can "read" through their fingers.

Interactive Maps

In this presentation we show how we produced tactile SVG maps that contain audio effects, haptic effects, voice annotations and embedded Braille fonts.

Audio

Our maps provide the user with audio feedback. For example, when the user moves the curser over a water element, a particular sound is played, when crossing a border another audio clip is heard, etc..

Haptic

Our maps contain haptic effects. We associated different types of vibrations to map features. The user requires a force feedback device, to take advantage of the haptic effects. We used the iFeel mouse from Logitech.

Voice Annotation

We added voice annotations to our maps. When the user clicks on a map feature, the name of that feature is spoken by the user's screen reader. Using these methods we are able to label any element on the maps. We either assume the user has installed a screen reader application or we can embed a text-to-speech application in the SVG file. We provide details on both techniques.

Maps, SVG and JavaScript

Our project has used several methods to generate interactive SVG files. In our most commonly used method the base map is created in Adobe Illustrator where the haptic effects are added through a JavaScript. The maps are then exported as SVG. The SVG code is then edited directly to add the audio effects. Another method is to open maps from existing databases and export them directly to SVG using DBx Geomatic's SVGMapMaker. We will show both approaches.

To create maps we either turned to commercially available maps that we scanned and redrew in Adobe Illustrator or used digital files from various sources. Our visual standards are then applied. This entails simplification of the line art and the elimination of details. A key part of the preparation is to assign names to all the elements that will be identifiable through the Text-to-Speech application. Then the layers are organised logically, regrouping elements of a similar nature. Finally interactive effects are added before the file is exported to SVG.

Conclusion

The emergence of the SVG format has finally made it possible to create maps that blind and vision-impaired persons can use. The role of the SVG format in our project is to create powerful information-rich interactive maps. Our solution combines online SVG maps with printed tactile maps that the user can touch and feel.

Much progress remains to be made in terms of reading and voice annotation. Work must also be done in the area of the user/machine interface. The installation of Aural Style Sheets in browsers as well as the integration of Voice XML will be a significant stage in assisting vision impaired persons to obtain geospatial information. But the good news is that maps for the blind and vision impaired are now a reality.

keywords: svg mapping, blind, vision impaired, accessibility, haptic, braille, voice