Thorsten Puck, Gerhard Weber
Harz University of Applied Studies and Research, Germany
Paper-based documents become accessible to blind people using automatic transcription services unless they contain graphics. But there are several classes of documents like letters, faxes or Web pages which rely on graphics to convey information and whose textual contents remain inaccessible. Like web pages may be "repaired" through alternate text descriptions, paper-based documents need to be enhanced for better automatic transcription including a review of images by the blind reader.
Through a novel process of printing high-resolution tactile images developed in project PRINT ( Puck 1998) a combination of tactile notation (Braille or Moon) and high quality presentation of graphics can be achieved.
As an example application we have implemented a fax system called TACFAX. As many blind people work as telephone operators, handling of faxes could be one of their tasks if they become accessible. TACFAX can be used for several tasks related to document processing by blind people including coloring of tactile images for people who have still a small sense of vision left. As Optical Character Recognition (OCR) cannot easily distinguish text from graphics a method for characterizing documents is needed without relying on help by sighted people. Zooming and resizing of parts of the document may improve the reader's understanding of a tactile printout.
With TACFAX faxes can be translated into Braille or Moon and printed on paper. Most kind of graphical elements in fax documents will be recognized automatically and be printed at the end of the Braille- or Moon-printout as an tactile image. For manual interaction with TACFAX we have implemented a non-visual user interface allowing keyboard input, speech synthesis and sound