**How Touchless was modified?**

We added the calibration application to interact with touchless SDK for better performance. The main purpose is to calibrate the resolution of the screen and the virtual display. The application is mainly to improve the accuracy of the markers interactions.

Figure 10 depicts the main classes of ATB. The first set of Classes includes the following classes: ActivateSystem, Marker, and CalibrationPoints. In the ActivateSystem class, the user (teacher or admin) can startSystem and EndSystem. While in the Marker class, the teacher can DefineMarker or add NewMarker. Moreover, the teacher or admin can setCalibrationPoints in the class CalibrationPoints. However, the class CalibrationPoints is aggregated to the class Marker; that is, if the user didn't define a Marker, he or she can't setCalibrationPoints. Also, the class Marker is aggregated to the class ActivateSystem. The teacher can't defineMarker or add newMarker without Activating the system first.

The second set of Classes includes three classes which are: Subject, Lesson, and Test. In the Subject class the user (Autistic User) can chooseSubject or close the Application. While in the Lesson class the user can start NewLesson, OpenLesson (open a previous lesson), SaveLesson, and CloseLesson. In the Test class, the user can start NewTest, RepeatTest (repeat a previous test), and check the TestScore. Also, the class Test is aggregated to the class Lesson, and the class Lesson is aggregated to the class Subject. That is, the user can't take a test if there is no lesson, and the user can't take a lesson if there is no subject.

#### **4.5 Using ATB**

Figure 11 depicts the sequence diagram of calibration process. The user "StartSystem()" to start the ATB System. After that, the admin should select "defineMarker" to define a new Marker. After defining a Marker, the admin or the teacher should carefully set the calibration points through selecting "SetCalibrationPoints()". This will set the dimensions of the whiteboard. Doing this process will convert the whiteboard to a smart interactive board. As a result, the user or the admin can interact with the whiteboard through hand gestures. So, he or she can run the Educational Applications to "chooseSubject()".

Fig. 10. Class diagram of ATB.

28 E-Learning – Organizational Infrastructure and Tools for Specific Areas

ATB mainly consists of three layers (Figure 9). The layers are: interface layer, tracking layer

The interface Layer consists of the PC desktop or the educational application. The user shall interact directly with the PC through the hand gestures to form different marker events (i.e.

This layer is the middle layer. It consists of the projector and the webcam. It helps convert the whiteboard to an electronic touch-screen, where any program can be controlled through hand gestures. The webcam will track the hand gestures through detecting pre-defined

This is the bottom layer, which consists of the Calibration Applications and Microsoft

 Calibration Application: It is software to measure the dimension of the PC's screen and represent it on the whiteboard through the projector. The main idea is to calibrate the

 Modified Touchless SDK: In this application we modified the click action to accomodate the interaction method. The code was modified so that the click event is generated if the user holds his hands/markers over an object (on the wall or screen) for around 2

We added the calibration application to interact with touchless SDK for better performance. The main purpose is to calibrate the resolution of the screen and the virtual display. The

Figure 10 depicts the main classes of ATB. The first set of Classes includes the following classes: ActivateSystem, Marker, and CalibrationPoints. In the ActivateSystem class, the user (teacher or admin) can startSystem and EndSystem. While in the Marker class, the teacher can DefineMarker or add NewMarker. Moreover, the teacher or admin can setCalibrationPoints in the class CalibrationPoints. However, the class CalibrationPoints is aggregated to the class Marker; that is, if the user didn't define a Marker, he or she can't setCalibrationPoints. Also, the class Marker is aggregated to the class ActivateSystem. The

The second set of Classes includes three classes which are: Subject, Lesson, and Test. In the Subject class the user (Autistic User) can chooseSubject or close the Application. While in the Lesson class the user can start NewLesson, OpenLesson (open a previous lesson), SaveLesson, and CloseLesson. In the Test class, the user can start NewTest, RepeatTest (repeat a previous test), and check the TestScore. Also, the class Test is aggregated to the class Lesson, and the class Lesson is aggregated to the class Subject. That is, the user can't

Figure 11 depicts the sequence diagram of calibration process. The user "StartSystem()" to start the ATB System. After that, the admin should select "defineMarker" to define a new Marker. After defining a Marker, the admin or the teacher should carefully set the

resolution of the pc screen to the dimensions of the white board.

seconds. The advantage of this method is that it is fairly simple.

application is mainly to improve the accuracy of the markers interactions.

teacher can't defineMarker or add newMarker without Activating the system first.

take a test if there is no lesson, and the user can't take a lesson if there is no subject.

**4.4 ATB design** 

and software layer. **a. Interface Layer** 

click, drag…etc.) **b. Tracking Layer** 

**c. Software layer** 

**How Touchless was modified?** 

Touch-less SDK.

**4.5 Using ATB** 

colors.

Fig. 11. Sequence Diagram of using ATB.

Towards Economical E-Learning Educational Environments for Physically Challenged Students 31

Fig. 13. Using ATB.

Fig. 14. Matching animals and voices game.

ATB has been tested by some young students and teachers. The initial feedback is positive. We are in the process of getting permission to deploy the system in real schools for autistic children to have concrete surveys and statistics regarding how ATB affected their education

**4.6 Assessments** 
