Scientific PDF document reader with simple interface for visually impaired people

We proposed our integrated system for scientific documents including mathematical formulae with,speech output interface [1], named "ChattyInfty." This system consists of recognizer, editor and speech interface for scientific documents. Using this system, visually impaired people can read printed scientific documents with speech output. In this paper, we propose a new additional function of this system, which recognizes PDF documents. Using this function, visually impaired people can also read PDF documents including mathematical formulae with ChattyInfty. If PDF documents have embedded text, our PDF recognition engine does not only recognize PDF documents as page images but also utilizes the text information to verify its recognition results, to improve the recognition results. Recent commercial OCR software usually provides PDF output. Combining it with our PDF reader, users can get integrated recognition results of any such commercial OCR with Infty's results of mathematical formulae. This system also provides simple interface customized for visually impaired people. It enables them to read scientific document (as image files / PDF) in minimum steps of key operation.