GraVVITAS 2.0: A Framework For Digital Accessible Content Provision
Cagatay Goncu, Kim Marriott · 2019 · Proceedings of the 21st International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS 2019) · doi:10.1145/3308561.3354586
Summary
This demonstration paper presents GraVVITAS 2.0 (Graphics Viewer using Vibration Interactive Touch and Speech), a framework for making graphical information accessible to people with vision impairments on off-the-shelf mobile devices. The paper argues that while screen readers have made textual information substantially accessible, graphical content — diagrams, tables, maps, charts, plots, and mathematical figures — remains largely inaccessible. Converting graphics to text descriptions loses critical information including geometric and topological congruence, spatial relationships, and the cognitive benefits of graphical representation. The current alternative, physical tactile graphics, is laborious, expensive, time-consuming to produce, and bulky to carry. GraVVITAS addresses this by providing a portable, pocket-sized solution using standard iOS devices. The framework consists of several integrated tools: GraViewer (the core presentation app that provides speech and haptic feedback as users explore annotated SVG graphics on a touchscreen — using the iPhone's built-in taptic engine or a custom HapticRing device on iPad), GraAuthor (a web-based authoring tool that lets teachers, transcribers, and family members create annotated SVG graphics), GraCalc (an accessible graphing calculator built on R), GraBook (a process for creating accessible ebooks with integrated text and graphics), and GraFloor (a computer vision tool for automatically transcribing floor plan images into accessible versions).
Key findings
GraViewer has been downloaded by 531 users worldwide since its March 2016 launch and received positive feedback for its portability and practical utility. Users have requested additional graphical content and new features. The framework uses annotated SVG as its non-proprietary interchange format, allowing content to be created in GraAuthor and consumed in GraViewer across any iOS device. The system provides multimodal feedback: speech announces graphic component labels and descriptions when touched, non-speech audio provides additional spatial cues, and haptic vibration indicates shape boundaries as users trace their fingers along edges. The content generation tools (GraCalc, GraFloor) aim to automate what has traditionally been a manual, expert-driven process — GraCalc lets authors simply specify a mathematical function to generate an accessible graph, while GraFloor uses computer vision to convert floor plan images automatically. These tools integrate with GraAuthor via a plugin system that outputs SVG documents. The framework is commercialized as the Raised Pixels Reader App on the Apple App Store, with research projects and collaborations remaining open source under a free-subscription model.
Relevance
GraVVITAS addresses a critical gap in accessible education: while text is well-served by screen readers, the graphical content that is essential to STEM education, geography, architecture, and data literacy remains largely locked away from blind and low-vision users. The framework's practical advantage over alternatives like refreshable braille displays (expensive), haptic devices like PHANTOM (specialized hardware), or physical tactile graphics (bulky, expensive to produce) is that it runs on devices people already own. The SVG-based approach is smart — SVG's inherent structure (shapes, layers, labels) maps naturally to accessible annotations, and the non-proprietary format avoids vendor lock-in. The authoring tool is particularly important because the bottleneck in accessible graphics is often content creation, not presentation technology. By enabling teachers and family members (not just specialist transcribers) to create accessible graphics, the framework could scale more broadly. The automation tools (GraCalc, GraFloor) push further toward reducing the human effort required. For accessibility practitioners working in education, this framework demonstrates a viable end-to-end pipeline from content creation to portable consumption of accessible graphics.
Tags: visual impairment · accessible graphics · tactile graphics · haptic feedback · data visualization · STEM accessibility · content authoring · SVG