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Information Technologies for Visually Impaired People
Figure 5: a) Web Page of a Digital Newspaper in a Conventional Browser. b) The same Page in NaviSAW.
the new accessible page can be saved.
To sum up, editSAW modifies the HTML code of original
Web pages, incorporating labels that make elements accessible
and others that will help naviSAW to provide added
accessibility options. These special annotations that
editSAW carries out form perfectly valid pages. Standard
browsers (Mozilla and Explorer) ignore these labels although
they show all the other attributes of the elements in
a conventional way. However, naviSAW will use these annotations
to offer improved accessibility to impaired users,
as described in Section 6.
5 The Braille Mouse: MouseSAW
Visually impaired users have the ability to overlap different
conceptual maps. mouseSAW uses this ability to
manage the browser as well as the contents represented
within it [5].
The mouse is shown in Figure 4. The main ideas have
been extracted from the VTMouse [6]. It was originally
designed for computer games, but has been configured and
programmed in our laboratory to represent useful information
in a haptic manner.
This mouse behaves in the same way as a conventional
mouse, but two cells of pins have been added. One of the
cells informs the user which panel is currently active. The
other one represents the element beneath the mouse pointer
(a table, an image, etc).
6 The Multimodal Browser: NaviSAW
NaviSAW is a multimodal browser that allows users to
access Web pages using different modes: visual, auditory
and tactile. All these modes are optional and compatible
with each other. The browser assists in selective surfing
based on the class of elements stored on a Web page, according
to the previous classification made in ontoSAW.
Figure 5 shows the normal appearance of a Web page in
a conventional browser and the final result, after being trans-
formed and displayed in naviSAW. Each element of the
original page is defined with an icon on the transformed
page. Take the Web page logo, for example.
Originally, it was positioned in the top left hand corner.
This element is classified as an “image” and transformed
into a specific icon. It maintains its original position, the
top left hand corner, on the transformed page. Another example
is the page menu, a list of links. This menu has been
transformed into a “list”. In this case, the element contains
other elements, the links. We can access these items using
the “expand” action defined for this type of element in
ontoSAW.
The naviSAW interface is divided into four panels, with
movement being restricted within each panel. If the user
wants to change the active panel, he has to use a combination
of keys or, alternatively, a voice command if the speech
synthesizer has been activated. Each panel has different
functionality; some of the panels are explained below:
Navigation panel. This contains the URL, "back",
"go to", "refresh", "stop" and "home" buttons, and also the
browser add-ons, such as the speech synthesizer, voice recognition
software and mailSAW, which is used for reading
mail.
Selective navigation panel (on the left of the screen).
This contains a button for each type of Web page element.
The element types are defined in the ontoSAW ontology.
When one of the buttons is pressed, a filter is activated over
the content of the page displayed.
Visualization panel (in the centre of the screen). The
Web page is represented in this panel. Each element of the
original Web page is represented as an icon. This icon stores
its position on the page in terms of rows and columns.
mouseSAW can surf through these elements, obtaining haptic
information from them. When the mouse pointer is positioned
over an element, a contextual menu appears. This
menu, called the “accessibility menu”, could be read out by
the speech synthesizer. Its content is dynamically obtained
70 UPGRADE Vol. VIII, No. 2, April 2007 © Novática