Methods of DAISY User Interaction With SVG Content

User Group: Blind Users,

Introduction

This is an overview of functionality requirements for blind users to have effective access to graphical information.

Audio-touch interaction

Audio-touch interaction requires a tactile copy and some type of hardware that lets a blind user request information about the tactile graphic and any object or text that may be in that graphic. The most common current hardware for this purpose is a touch-sensitive pad on which the tactile copy is placed. That hardware provides information to a computer that then speaks information about the point indicated by the user. SVG graphics can contain text and graphical objects. Graphical objects in SVG may have titles and descriptions. Users generally expect to hear an object title when it is selected and to be able then to take some action that will read the description.

Although the term "audio/touch" is used, there is no reason that the audio portion could not be represented in braille displayed on an on-line braille display. This is functionality that deaf-blind users need.

List of required functionality

• Important graphical objects and text in the tactile graphic must be tactually differentiable
• A user must be able to hear text spoken when it is selected
• A user must be able to hear the title of important graphical objects when selected
• Users must be able to access audio information with an on-line braille display if desired.
• A user should have some way to request additional descriptive information about objects
• A user should have some way to hear the title and description of the total figure

Minimal Audio-only interaction

Minimal audio information is what one should be able to obtain from any DAISY reader whether or not it supports any interaction with details of the SVG graphic.

List of required functionality

• User must have the opportunity to hear the figure title and description from any DAISY viewer

Maximum Audio-only Interaction

A user with access to a SVG viewer should be able to obtain a considerable amount of information from the file even without a tactile copy. These file details can often give a user an excellent understanding of the information in the graphic. An SVG expert can read the whole file, but eben those who know nothing of SVG should be able to obtain the information listed below.

List of required functionality

• User needs the capability of navigating in audio or braille to an ordered list of graphical objects in a figure
• User should be able to read object titles and descriptions in list using audio or braille