Constructing Moving Pictures Eyes-free: An Animation Tool for the Blind Hesham M. Kamel and James A. Landay Group for User Interface Research, Computer Science Division University of California, Berkeley Berkeley, CA 94720-1776 USA +1 510 643-7354
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[email protected] ABSTRACT
Visually impaired people constantly interpret moving phenomena in the real world; they do not lack the skills to understand the meaning of what is portrayed in an animation. However, today there is no method that allows them to create computer-based animation. We have extended IC2D, a drawing tool for the blind, to allow users to construct animation based on their drawings by defining rotation, swing, and path motions. Keywords
Visually impaired, drawing, IC2D
animation,
assistive
technology,
INTRODUCTION
As computer interfaces have become increasingly graphical, such as by employing visual metaphors of files and folders, researchers have developed methods for presenting graphical user interfaces (GUIs) in non-visual formats to allow access for visually impaired users [5]. There are many advantages in representing aspects of content using graphics and animation for sighted users. Designers should not forgo these advantages because of visually impaired users. Rather, we look at this as a challenge to develop methods for transforming visual semantics into a non-visual format. Researchers have developed tools for making graphics accessible to visually impaired users, allowing them to access graphics [5], identify shapes [3] and create drawings [2, 4], but have not yet addressed the issue of animation. We believe it is helpful to conceptualize animation as another form of graphical output, which with proper interface design and labeling can be made meaningful for blind users. Further, with a proper interface, blind users can create animations for communication and creative expression. Sighted people commonly think that a person who cannot view an animation would have no desire to create one.
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Further, it is a common misconception that blind people, for lack of being able to see, somehow have an impoverished imagination. In fact, blind people have wideranging imaginations, just as sighted people do. As an example, enjoyment of movies demonstrates that blind people do not confine their imagination to static, 2-d pictures. Blind individuals, when given proper tools, can express their creative imagination in a variety of mediums. For example, Lisa Fittipaldi [1], after learning that her sudden loss of vision was permanent, began in 1995 to explore painting as a means of creative expression. A selftaught artist, she often draws her inspiration for her works from experiences in daily life, visiting distant places and listening to movies. For example, she created her painting “Ranjapur,” after listening to the movie “The Rains of Ranjapur.” Despite her visual impairment, she has created works that are collected and exhibited internationally. An accessible animation program can give blind people another option for manifesting their creativity and reflecting their mental models. In this paper, we illustrate how the IC2D system together with its animation extension allows blind users to create moving pictures by directly manipulating on-screen objects. THE DRAWING TOOL
IC2D provides visually impaired users a medium to create, view and assign semantics to drawings [2]. Its reference grid and navigation system are metaphorically based on a 3×3 grid with the same numbering arrangement as a telephone keypad. A recursive grid scheme allows users more precise point selection (up to 27×27 cells). Pull-down menus are replaced with grid-based palettes for effective navigation. IC2D has two different modes: in the drawing mode, the user can create and view drawings at a high level or in detail. In the labeling mode, the user can assign a label to a single object or to a group of labeled objects presented in a hierarchical labeling structure. Navigation keys and all functions are accessed through the computer keyboard, and voice synthesis provides feedback to the user. ANIMATION SUPPORT
IC2D’s animation extension allows the user to create animations using three types of motion commands: move,
rotate, and toggle. To animate an object or group of objects through motion, the user chooses starting and ending positions using IC2D’s standard navigation and selection keys, where the ending position determines the direction of the animation. The animation is smoothly played out by moving the object a small amount each frame. This rate is set to a default, but can be adjusted for each object. The user can also rotate an object or group of objects clockwise or counterclockwise (e.g. rotating the wheels of a car while the animation moves it across the screen). The user defines the center of rotation for the object(s). The user can also swing, or toggle, objects. This rotates the chosen objects around the user-defined base point approximately 45 degrees clockwise from the centerline, then to a position 45 degrees counterclockwise from the centerline, etc. This gives the effect of the object swinging left and right around the chosen position. This feature is useful for animating a dog wagging its tail; the tail can swing back and forth around its position of attachment to the body. Another potential use is for simulating a grandfather clock ticking. One can animate the pendulum of the clock to swing back and forth around the top position of the pendulum.
commands moves the helicopter from right to left across the screen. To rotate the rotors, the user again selects it in labeling mode, and then chooses the “rotate left” control. The user is then prompted to select the preferred point of rotation. Here the user enters the center position of the propellers. Finally, to give the effect of the sun shimmering, the user employs the toggle control. In labeling mode, the user selects the group labeled “sun,” and chooses toggle. The user selects the center position of the sun as a base point. Finally, the user selects “animate now” from the animation palette to set the objects in motion (see Figure 2a). The sun, which is originally hidden by the green horizon, rises and shimmers, while the helicopter flies by, rotors spinning in 2-d (see Fig. 2b).
The user can also select a sound file to play while the animation is in motion. All animation functions are accessed via an animation palette (see Figure 1).
Figure 2. Sunrise: (a) before animation, (b) after animation.
Figure 1. IC2D Animation Palette also uses grid metaphor
REFERENCES 1. Fittipaldi, Lisa. http://lisafittipaldi.com/
User Controls
In the following example, the sun rises up from the horizon and swings about its center. Simultaneously a helicopter flies by with its propellers rotating (Figure 2). To move the sun from the bottom to the top of the screen, the user employs the motion animation control. First, the user switches to labeling mode. Using the navigation keys, the user moves through the hierarchical labeling structure and reaches a group of objects labeled “sun.” The user then selects the group and activates the animation palette. The user moves the cursor to “animate” and selects it. The user is then prompted to enter the animation’s starting position, and so selects one of the positions associated with the sun. The user is next prompted to enter the target position, and selects the topmost center grid position. A similar set of
CONCLUSION
The IC2D animation extension enables visually impaired users to view and create animations. We combined a technique for drawing with a method for hierarchical labeling, and applied a set of user controls: motion, rotation, and toggling to produce an animation method for the blind. This schema provides visually impaired people with another method to express their creativity and communicate through another form of graphical output. Further, we hope that by making what seems impossible possible, we might increase communication between blind computer users and the sighted world.
2. Kamel, H.M. and J.A. Landay, A Study of Blind Drawing Practice: Creating Graphical Information Without the Visual Channel, in Proceedings of Assets 2000, pp. 34-41. 3. Kamel, H.M and P. Roth and R.R. Sinha. Graphics and User’s Exploration via Simple Sonics (GUESS): Providing Interrelational Representation of Objects in a Non-visual Environment, ICAD 2001 Proceedings, pp. 261-266. 4. Kurze, M. TDraw: A Computer-Based Tactile Drawing Tool for Blind People. In Proceedings of Second Annual ACM Conference on Assistive Technologies: Assets '96. pp. 131138. 5. Mynatt, E.D., Transforming Graphical Interfaces into Auditory Interfaces, Unpublished Ph.D., Georgia Institute of Technology, Atlanta, Georgia, 1995.
