Auditory presentation of graphical user interfaces

oriented textual output displayed on the screen was stored in the computer’s framebuffer. An access program could sim-ply copy the contents of the framebuffer to a speech synthe-sizer, a Braille terminal or a Braille printer. Conversely, the contents of the framebuffer for a graphical interface are sim-ple pixel values. To provide access to GUIs, it is necessary to intercept application output before it reaches the screen. This intercepted application output becomes the basis for an off-screen model of the application interface.The information in the off-screen model is then used to create alternative, acces-sible interfaces. The goal of this work, called the Mercator1 Project, is to pro-vide transparent access to X Windows applications for com-puter users who are blind or severely visually-impaired [ME92]. In order to achieve this goal, we needed to solv