The Visual Total Access System (VTAS) extends the Total Access System to provide individuals who are blind with external access to information displayed on the screen.
A Visual TAP (VTAP) retrieves screen information from the video signals the PC sends to the display screen. The VTAP captures a bitmap image of selected screen areas and uses pattern recognition to detect text, icons and graphical areas. The recovered information is encoded, using a universal protocol, and sent to an accessor that translates the screen information into accessible formats such as: spoken text, Braille (tactile), force feedback (haptic), or sonic representations such as chords or 3D sounds.
Accessor (Input)
A personalized device that provides its user with his or her preferred interaction modalities. Options range from specialized keyboards and pointing devices through to sophisticated speech recognizers, head trackers and eye gaze trackers.
Accessor (Output)
A personalized device that provides a blind user with his or her preferred display modalities. Options include: Braille (tactile) , spoken text, force feedback (haptic), or sonic representations such as sounds or chords that uniquely represent icons.Total Access Port (TAP)
A small keyboard and mouse emulator that provides direct access to any user accessible functions on the target computer. The TAP has no impact on the normal operation of the PC. A blind person may not require a TAP if they substitute keyboard commands for mouse functions.Visual Total Access Port (VTAP)
A screen capture and pattern recognition system that extracts information from the video stream generated by a PC. The VTAP has no impact on the normal operation of the PC.Universal Protocol
A communication protocol that allows any accessor to connect to any TAP. The connection can be wired or wireless (Infrared or Radio).
Advantages of the VTAS
- A person who is blind can operate any device that has a VTAP.
- No drivers or software modifications are loaded in the target system.
- An accessor can be as simple or as complex as is required by the user.
- An accessor can be used for a very long time since it is independent of the target hardware, operating system and applications.
- Accessors are immune from version obsolescence initiated by the software OS and application manufacturers.
- The providers of the IT infrastructure don't need to know about disabilities.
- The responsibilities and costs of providing access are shared between the user who provides a personal accessor, and the provider of the IT infrastructure who provides a VTAP.
