Virtual Keyboard On Screen Keyboard Computer Science Essay

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On screen keyboard or virtual keyboard is a projected keyboard layout displayed on the screen for the use of different programs that requires input from a keyboard. The interface can then be used with any pointer device. A standard mouse is generally used but a number of alternatives are available that addresses different kinds of disabilities. These alternatives, according to Public Service Commission of Canada (2007) include 'foot/toe mouse, touchpad, trackballs, infrared/camera (optical mouse) and sip 'n' puff switches.'

2.1.2 Eye Tracking

Eye tracking is the process of measuring either the point of gaze or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement.

According to Eye trackers measure rotations of the eye in one of several ways, but principally they fall into three categories.

One type uses an attachment to the eye, like a special contact lens with a mirror or a sensor embedded magnetic field, and the movement of attachment is measured with the assumption that it does not slip significantly as the eye rotates. Measurement with fitting contact lens has a very sensitive recording of eye movements, and magnetic search coils are the method of choice for researchers studying the underlying dynamics and physiology of eye movements.

The second broad category uses non-contact, optical method for measuring eye movements. Light, usually IR, reflected in the eyes and feel with a video camera or some other optical sensor designed specifically. This information is then analyzed to extract eye rotation from changes in the reflection. Video based eye trackers typically use the corneal reflection and the center of the pupil as to detect features from time to time. A more sensitive type of eye tracker, the dual-Purkinje eye tracker uses reflections from the front of the cornea and the back of the lens as features to track. A more sensitive method is to image features from inside the eye, such as retinal blood vessels, and follow these features as the eye rotates. Optical methods, particularly those based on video recordings, are widely used and preferred to gaze tracking for non-invasive and inexpensive. (Crane & Steele, 1985)

The third category uses potential measured using electrodes placed around the eyes. It is the origin of the stationary electric field, which can also be detected in total darkness, and if the eyes are closed. It can be produced by the dipole model to the positive pole of the cornea and the negative pole of the retina. The electrical signals that can be derived using two pairs of electrode contacts placed on the skin around the eyes are called Electrooculogram (EOG).

EOG is a technique for measuring the resting potential of the retina. It is a very light-weight approach that, in contrast to current video-based eye trackers, only requires very low computational power, works under different lighting conditions and can be implemented as an embedded, self-contained wearable system. (Bulling, Roggen, & Tr'ster, 2009) It is thus the method of choice for measuring eye movement in mobile daily-life situations and REM phases during sleep.

2.2 Eye Tracking Related Researches and Products

In developing this study, we have found several researches that have similar study to this topic. These products and previous studies were useful to us as guidelines and provided a lot of details to help accomplish all of the objectives.

2.2.1 Eye-Gaze Response Interface Computer Aid (ERICA)

Eye-Gaze Response Interface Computer Aid (ERICA) is a device that tracks eye movement to enable hands-free computer operation. From the features of the current portrait, the interface calculates the approximate location of the user's eye-gaze on the computer screen. The computer then executes commands associated with the menu option currently displayed at this screen location. In this way, the user can interact with the computer, run applications software, and manage peripheral devices-all simply by looking at an appropriate sequence of menu options displayed on the screen. (T.E., White, Martin, Reichert, & Frey, 1989) The device can also deliver a synthetic voice output. The technology can allow users to speak, write e-mail, surf the internet, create documents, or play games through eye movement alone. No keyboard or mouse is needed. (Reitan, 2005)

2.2.2 Eyegaze Edge

With the Eyegaze Edge people with physical disabilities can do many things with their eyes that they would otherwise do with their hands. Simply by looking at control keys displayed on a computer monitor screen, the user can perform a broad variety of functions including speech synthesis, environmental control, sending emails, browsing the Internet, playing games, typing, and controlling most PC and MAC computers.

It is a communication and control system for people with complex physical disabilities. The system is operated entirely with the eyes. By looking at control keys displayed on a screen, a person can synthesize speech, control his environment (lights, call bells, etc.), type, run computer software, operate a computer mouse, and access the Internet and e-mail. Eyegaze Edge Systems are being used to write books, attend school and enhance the quality of life of people with disabilities all over the world. (LC Technologies, Inc., 2009)

2.2.3 Opengazer

Opengazer is an application that uses an ordinary webcam to estimate the gaze direction of users. This information can then be sent to another application. For example, opengazer allows writing with eyes when used in conjunction with Dasher. The software aims to be cheap alternative to commercial hardware-based eye trackers. (Nel, 2009)

2.2.4 A Single Camera Eye-Gaze Tracking System with Free Head Motion

This paper describes the design, implementation and evaluation of an eye-gaze tracking system that meets key requirements as described in the introduction. The single camera, multiple glint system achieves the accuracy claimed in the presence of free head motion within the field of view of the camera. Over various combinations of hardware configurations and subjects the best accuracy achieved with the eye away from the calibration. System accuracy is highest at the calibrated position and degrades slightly as the head is moved away. (Hennessey, Noureddin, & Lawrence, 2006)

2.2.5 A Communication System for ALS Patients Using Eye Blink

The purpose of the study is to design a communication system for ALS patients who are unable or finds it hard to use their hands and mouth. In the proposed system, eye blink is used as a switch to tell judging patient's intention by using several image processing. A list of intentions is displayed on the PC monitor; each intention is displayed with an adequate time interval. The patient can select the candidate intention by blinking his/her eye. (Takeshita, Uchibori, Mizukami, Satoh, Tanaka, & Uchikado, 2003)

2.2.6 Eye-Writing Communication for Patients with Amyotrophic Lateral Sclerosis

The study attempts to predefine eye writing method with a symbol set containing symbols with distinct writing traces. A user of this method rotates his or her eye balls to "write" a symbol according to its designated writing trace. Meanwhile, the eye movement is detected using a suitable technique such as the electroculography, which measures voltage differences on the skin around the user's eyes. Distinct features of the acquired eye-movement signals are extracted in order to determine which symbol, among those in the symbol set, the user's eyes have just written. An eye-writing system has been implemented in this study. Tests on subjects with no known disabilities have been conducted and the performance has been evaluated. The study found that eye-writing system is potentially useful for facilitating communication of sever ALS patients who have lost most of their oral speaking and handwriting abilities. (Tsai & Chen, 2009)

2.3 Conclusion

This chapter briefly reviews all related and required literatures, which are needed for the study. It focuses on the similarities and differences of the system to earlier research. These similarities and the differences of our research compared to others described in table below. Eclipse

From its official website, 'Eclipse is an open source community, whose projects are focused on building an open development platform comprised of extensible frameworks, tools and runtimes for building, deploying and managing software across the lifecycle.' (The Eclipse Foundation, n.d.) It is an integrated development environment that can be used to develop in multiple languages such as C++, PHP, Pyhton and Ruby.

Official site: Netbeans IDE 6.9.1

The official Netbeans' website describes that:

Netbeans is an open-source project dedicated to providing rock solid software development products (the NetBeans IDE and the NetBeans Platform) that address the needs of developers, users and the businesses that rely on NetBeans as a basis for their products. (Oracle Corporation, n.d.)

The IDE is free both for commercial and non-commercial use. The IDE can be used to develop applications in multiple languages such as Java, JavaScript, PHP, C, C++ and others. It is also a multi platform operating system where it can be run anywhere with Java Virtual Machine installed.

Official site: Camera Mouse 2011

The description of Camera Mouse 2011 from its official website tells that:

Camera Mouse is a program that allows you to control the mouse pointer on a Windows computer just by moving your head. The program was developed to help people with disabilities use the computer. The main audience for this program is people who do not have reliable control of a hand but who can move their head. People with Cerebral Palsy, Spinal Muscular Atrophy, ALS, Multiple Sclerosis, Traumatic Brain Injury, various neurological disorders use this program and its predecessors to run all types of computer software. Camera Mouse works as a mouse replacement system for Windows computers so it should work with just about any application program. For example people use Camera Mouse with entertainment programs, education programs, communication programs, web browsers, and so on Camera Mouse works best with application programs that require only a mouse and a left click and that do not have tiny targets. (About/Camera Mouse, 2010)

3.3 Conclusion

This chapter explains the methodologies that must be taken for the research. The System Development Life Cycle (SDLC) has been followed to develop this study to ensure organized work flow and also helps to reduce mistake that may occur at any time during the process.