Helsingin yliopisto


Helsingin yliopiston verkkojulkaisut

Helsingin yliopisto, Helsinki 2006

Näkövammaisten tietokoneavusteinen tiedon hankinta

Lauri Lahti

Pro gradu, huhtikuu 2006.
Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, tietojenkäsittelytieteen laitos.

Computer-assisted acquisition of information for visually impaired

Master's thesis, April 2006.
University of Helsinki, Faculty of Science, Department of Computer Science.


The study examines various uses of computer technology in acquisition of information for visually impaired people.

For this study 29 visually impaired persons took part in a survey about their experiences concerning acquisition of infomation and use of computers, especially with a screen magnification program, a speech synthesizer and a braille display. According to the responses, the evolution of computer technology offers an important possibility for visually impaired people to cope with everyday activities and interacting with the environment. Nevertheless, the functionality of assistive technology needs further development to become more usable and versatile.

Since the challenges of independent observation of environment were emphasized in the survey, the study led into developing a portable text vision system called Tekstinäkö. Contrary to typical stand-alone applications, Tekstinäkö system was constructed by combining devices and programs that are readily available on consumer market. As the system operates, pictures are taken by a digital camera and instantly transmitted to a text recognition program in a laptop computer that talks out loud the text using a speech synthesizer.

Visually impaired test users described that even unsure interpretations of the texts in the environment given by Tekstinäkö system are at least a welcome addition to complete perception of the environment. It became clear that even with a modest development work it is possible to bring new, useful and valuable methods to everyday life of disabled people. Unconventional production process of the system appeared to be efficient as well.

Achieved results and the proposed working model offer one suggestion for giving enough attention to easily overlooked needs of the people with special abilities.

ACM Computing Classification System (1998):
K.4.2 Social Issues: Assistive technologies for persons with disabilities
I.4.9 Image processing and computer vision: Applications

Keywords: Visually impaired, computer-assisted, information, acquisition, assistive technology, computer, screen magnification program, speech synthesizer, braille display, survey, testing, text recognition, camera, text, perception, picture, environment, trasportation, guidance, independence, vision, disabled, blind, speech, synthesizer, braille, software engineering, programming, program, system, freeware, shareware, open source, Tekstinäkö, text vision, TopOCR, Autohotkey, computer engineering, computer science

Additional information available from the author: Lauri.Lahti@oi.fi

The title page of the publication

Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.

© Helsingin yliopisto 2006

Viimeksi päivitetty 02.05.2006

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