PowerReader: Making PowerPoints Accessible to the Visually Impaired
In today’s educational environment, lectures are often accompanied by slide shows, which display supplementary texts, related images, graphs, and diagrams to support understanding of the material. While presentation software such as Microsoft PowerPoint and Apple Keynote include tools to make presentation slides more accessible to screen readers, they are rarely used. Our analysis of over 12,000 university-level course slides available online showed that only 1.67% of the images contained in the slides provided alternative textual descriptions. More shocking is that the majority of alternative descriptions were simply the image filename (e.g. Figure1.jpg). Only 8 of the 8689 images we sampled contained a useful alternative description.
To address these issues, we developed PowerReader, a tactile and audio system that takes advantage of crowdsourcing to make PowerPoint slides accessible to the vision impaired. PowerReader works by taking a PowerPoint presentation and extracting non-accessible elements from the presentation. Graphical elements such as images and graphs are sent to a crowdsourcing platform to construct textual descriptions of the elements. Mathematical equations are translated by our math translator component. Elements and their textual descriptions are then combined with the original content to construct screen-reader accessible text and PowerPoint slides. In addition, graphs and charts are also parsed so that they can be viewed on our custom built tactile display.