Cagatay Goncu

GraVVITAS: generic multi-touch presentation of accessible graphics

Access to graphics and other two dimensional information is still severely limited for people who are blind. We present a new multimodal computer tool, GraVVITAS, for presenting accessible graphics. It uses a multitouch display for tracking the position of the users fingers augmented with haptic feedback for the fingers provided by small vibrating motors, and audio feedback for navigation and to provide non-geometric information about graphic elements. We believe GraVVITAS is the first practical, generic, low cost approach to providing refreshable accessible graphics. We have used a participatory design process with blind participants and a final evaluation of the tool shows that they can use it to understand a variety of graphics - tables, line graphs, and floorplans.

Tactile chart generation tool

We have implemented a Java application that automatically generates tactile bar and pie charts from data values given in a formatted text file. The tool is designed to semi-automate the construction of tactile versions of bar and pie charts in educational material. The tool provides a wide variety of layout styles. While the tool allows the user to fine tune the layout, the generated SVG diagram can also be modified in a standard diagram editor.

Usability of accessible bar charts

Bar charts are one of the most commonly used diagram types. Tactile diagrams are a widely used technique for presenting graphics to people who are blind. We explored how to present bar charts using a tactile presentation. Our user study used blind participants and evaluated both user preferences and performance. We found that providing grid lines and values in a tactile diagram was preferred to a direct transcription. In addition, presenting the data as a tactile table was preferred to a tactile chart. Both of these approaches reduced the error rate, and presentation as a table had performance benefits. We also investigated the comparative usability of: a tactile presentation, an audio description of the bar chart, and a tactile/audio presentation in which a tactile diagram is overlaid on a touch-sensitive device which provides audio feedback on demand. We found that tactile was the most preferred while audio was the least.

Accessible On-Line Floor Plans

Better access to on-line information graphics is a pressing need for people who are blind or have severe vision impairment. We present a new model for accessible presentation of on-line information graphics and demonstrate its use for presenting floor plans. While floor plans are increasingly provided on-line, people who are blind are at best provided with only a high-level textual description. This makes it difficult for them to understand the spatial arrangement of the objects on the floor plan. Our new approach provides users with significantly better access to such plans. The users can automatically generate an accessible version of a floor plan from an on-line floor plan image quickly and independently by using a web service. This generates a simplified graphic showing the rooms, walls, doors and windows in the original floor plan as well as a textual overview. The accessible floor plan is presented on an iPad using audio feedback. As the users touch graphic elements on the screen, the element they are touching is described by speech and non-speech audio in order to help them navigate the graphic.

Understanding the graphical challenges faced by vision-impaired students in Australian universities

ABSTRACT Information graphics such as plots, maps, plans, charts, tables and diagrams form an integral part of the student learning experience in many disciplines. However, for a vision impaired student accessing such graphical materials can be problematic. This research seeks to understand the current state of accessible graphics provision in Australian higher education. We conducted an online survey of 71 vision-impaired university students and semi-structured interviews with 44 key stakeholders (students, academics, disability liaison officers and accessible graphics providers). We found that difficulty in accessing graphical materials was a barrier to many vision-impaired students and that there were systemic problems with current processes for accessible graphics provision. Recommendations are made on ways to address these concerns in order to provide a more equitable higher education experience.

ContextuWall: Peer Collaboration Using (Large) Displays

The emerging field of Immersive Analytics investigates how novel display and interaction technologies can enable people to visualise and analyse data and complex information. In this paper, we present ContextuWall, a system for interactive local and remote collaboration using touch and mobile devices as well as displays of various sizes. The system enables groups of users located on different sites to share content to a jointly used virtual desktop which is accessible over a secured network. This virtual desktop can be shown on different large displays simultaneously, taking advantage of their high resolution. To enable users to intuitively share, arrange as well as annotate image content, a purpose-built client software has been built and can easily be adapted with plug-ins for existing data analytics software. We show exemplary use cases and describe the system architecture and its implementation.

Generation of accessible graphics

Information graphics are common in written communication. The ability to comprehend, use and create these graphics is an important skill that most of us take for granted. However, for those who are visually impaired, access to such graphics is severely limited. While new presentation technologies will improve access, an unsolved problem is how to automatically generate an accessible version of an information graphic. We describe the goals and approach of a project to develop software tools to do this. Our proposed approach uses advanced graphics recognition combined with high-level transformation. It is designed to handle a wide variety of information graphics, including floor plans, line graphs and organisation charts, and to be usable in schools, workplaces and at home.

Tactile diagrams: worth ten thousand words?

The properties that make diagrams more effective than text in certain circumstances have been investigated by researchers for over 20 years. However, this research has focused on visual diagrams. To the best of our knowledge, no research has yet investigated whether the same benefits and properties hold for tactile diagrams, which are blind peoples primary means of access to diagrams. We present a consideration of similarities and differences in the properties and potential benefits of visual and tactile diagrams; and suggest where experimental investigation would be useful.

Creating eBooks with Accessible Graphics Content

We present a new model for presenting graphics in eBooks to blind readers. It is based on the GraViewer app which allows an accessible graphic embedded in an iBook to be explored on an iPad using speech and non-speech audio feedback. We also introduce a web-based tool, GraAuthor, for creating such accessible graphics and describe the workflow for including these in an iBook. Unlike previous approaches our model provides an integrated digital presentation of both text and graphics and allows the general public to create accessible graphics.

GraCALC: An Accessible Graphing Calculator

We present a new approach for providing mathematical and statistical graphics to people who are blind or have severe vision impairment and describe the implementation and initial evaluation of an accessible graphing calculator, GraCALC. GraCALC automatically creates a graphic from a specification of the function or a tabular data using a web based service. The graphic is then presented on a touch device, and a mixture of speech, non-speech audio and optional tactile feedback are provided to allow the users explore the screen. An overview containing a sonification of the graphic and a description similar to that created by a human transcriber is also automatically generated so as to help the user in their initial navigation.