A New Web Course —"Fundamentals of Image Processing and Analysis" Yu-Jin ZHANG Wei-Jin LIU Department of Electronic Engineering, Tsinghua University, Beijing, China 100084 E-mail: zhangyj@ee.tsinghua.edu.cn A new Web course called "Fundamentals of Image Processing and Analysis" has been developed recently. This Web course is suitable for continuous education and distance learning. In this paper, the basic properties should be fulfilled by a Web course are first discussed. With respect to these properties, different factors that should be considered in the design and implementation of Web courses are then explained. Based on these discussions and explanations, the course structure is determined and the implementation is carried on. The course structure is a combination of tree structure and graph structure, which has the advantage for tractable navigation and hierarchical configuration. The knowledge component is taken as the logical unit for study, and various content representations are organized around each knowledge component. Different components, interface and screen layouts, especially those related to demonstration, are illustrated to show the characteristics of the course. Finally, with an overview of the course composition, some merits of the general design considerations and the developed course in particular are discussed. Key word: Distance learning Continuous education Web course Course structure Course design Courseware design Learning Strategy Interactive environment 1 Introduction The new century has been marked by the advent of information technology and the maturing of telecommunication technology. This progress has both impacts on the contents of education and on the means of education. In one side, multimedia, especially image (contain picture, animation, video, etc.) gets more and more attention and application [6]. In another side, using Internet for teaching and learning is increasingly widespread now. As a joint "effort", many Web courses have been designed and developed to meet the requirements of continuous education and distance learning. Web course is a somehow general and rough concept, normally, it includes the contents of education for a course or discipline and the practice of teaching. The contents should be well organized according to the education goals and education strategies. While for the education practice, the appropriate supporting environment (such as software tool supporting the Web-learning as well as education resources) is also very important [5]. This paper describes a new Web course named "Fundamentals of Image Processing and Analysis". Compared to some existing courses in related topic (for example, [1]), this course is targeted specially to continuous education program for working people [5]. They have obtained their diplomas in other disciplines than computer sciences and electronic engineering but facing the challenge of image technique. They are working different regions with more than thousand kilometers apart from each other, and have sparse time to follow the course lecture or contact teacher. This paper will first discuss some general factor influence the performance of Web courses, and then will narrow the focus to the implementation of the specific Web course in counting the above particular problems. The structure, interface, layout, functional modules, and some components of the course will be detailed. 552 2 General Designing Considerations As a new means of education, Web course has some own characteristics. Construction of Web courses should take into consideration of the particularity of distance learning, satisfy the condition of running in the Internet, and profit the advantage of network environment. To our opinion, the following properties should be fulfilled by a Web course [5], [8]: (1)It is advanced in the sense of reflecting the current trend in the development of discipline; (2)It keeps the initiative in reader's own hands to prompt their motivation and consciousness in learning; (3)It is opened so the structure and content of course could be easily extended, adjusted and replaced; (4)It supports different users' sharing of the resources in and/or out class; (5)It provides easy interaction between human-machine, teacher-student and teaching-learning [7]; (6)It endorses collaboration so learning task could be fulfilled by discussion and co-operation. Web course design is an important task, and has significant influence on the course performance and education effects. According to the above discussions, the following factors should be considered in the design and implementation of Web courses: (A)Information resources: The property(1),(2)and(3)should be considered mostly here. The course arrangement can be used to guide the students' self-learning. To this end, various kinds of information resources need to be managed to support learning, but not only teaching. (B)Content organization: The property(1) (3) , and(4)should be considered mostly here. The contents are to be organized in modules. In particular, it is better to use knowledge component (KC) as learning/studying units, and to arrange contents around knowledge points. (C)Course structure: The property(3)and(5)should be considered mostly here. A dynamic and layered structure supporting association of related KCs is important. The concepts, theorem and laws in the course should be linked to support cross-reference. (D)Content representation: The property(5)and(6)should be considered mostly here. Different media, such as image/picture, animation, audio and video should be employed to give readers some vivid and dynamic representation to stimulate their deep thinking and active participation. (E)Course navigation: The property(2)and(5)should be considered mostly here. According to the education plan, the course structure and index list should be provided. Following these structures and lists, some simple, legible and explicit navigation functions will guide the readers pass through the whole course effectively [7]. 3 Course Structure and Implementation According to the above discussions, the course is organized in a modular manner, with each module refers to one separate study unit. In turn, each study unit is composed of a number of components that have embedded also the teacher's teaching experience. The set of resources available for each study unit includes text notes and examples ( with formula, tables, drawing and pictures ) , interactive demonstrations, self-tests as well as introduction/indication and list of references. They provide different possibilities for learning, and permit reader using different styles of learning to enhance the study [2]. The designed structure of the Web course is sketched in Figure 1. When the course started, five lists are accessible. The KC (Knowledge Component) title list provides a list of knowledge elements, which servers as the content of the course. Other four lists are composed of a number of pop-up content modules, each has a particular function. Look at Figure 1 horizontally, each KC is made of component modules from all four lists. The course structure is a combination of tree structure and graph structure. The tree structure provides a fast and logical way of access to different branches of the course. On the other side, the graph structure makes the navigation quite easy and nature. 553 Introduction KC T itle List Kowledge Componen t Kowledge Componen t Kowledge Componen t Course Example List Demo List Self-T est List Reference List KE T itle Example Demo Self-T est Reference KC T itle Example Demo Self-T est Reference KC T itle Example Demo Self-T est Reference Figure 1 Structure of the course The Web course, in fact, is composed of a number of Web pages. Since the Web course is accessible from Internet, so people could use some net browser tools (for example, IE) to get into its pages. Web page is the physic unit of this Web course, that is, each studying unit in this Web course corresponds to an individual Web page. The navigation among different KC, such as between former and next page can be easily accomplished using functions provided by browser. The navigation in the courseware is an important factor of the effectiveness. Both linear organization and explorative organization are required [3]. To facility the navigation, a mixed data structure with four levels is used to organize the contents. It is a combination of a net structure and a tree structure as shown in Figure 1. Figure 2 gives the start screen layout of the course; the structure in Figure 1 has been embedded inside it. The left column shows the KC title list, titles are gathered into several groups corresponding to different chapters in the content. Each title is corresponded to a section. The right window is the main display window for course content. At the top of the right Windows, the navigation bar/list access icons are displayed. They will keep there despite the roll of contents in the window, so the readers can make the link to required module/component all the time. In Figure 2, the table of contents on the left of the screen represents the hierarchical structure of the hypertext document, and each entry in the table of contents is a hypertext link. Figure 2 Screen layout of the course The organization of each KC unit is shown in Figure 3. It can be accessed by selecting the appropriate KC title. It is composed text for explanation, tables and formulae, as well as examples, demos and self-test. Examples and demos are made of pop-up Windows, so the representation in the KC unit is clear and concise. Reference is provided for each KC, however, to help the reader to concentrate on the course content first, references for related KC are grouped together, and made accessible from the table of content. While, example, demo and self-test are directly accessible from KC unit, of course, they can be also selected from their respective lists, as shown by the connections in Figure 3. 554 KC T itle Text / Table / Formula Example Example List Demo List Self-T est List Demo Text / Table / Formula Demo Reference for KC group Example Text / Table / Formula Self-Test Figure 3 Organization of KC unit Figure 4 gives a screen layout of a typical KC unit, it can be selected from the table of content from the left column. In the right window, test is not only used for the explanation of basic concepts and principle, but also served as the vehicle for conducting the course content. In fact, tables and formulae are embedded in the text flow, as well as the hot-key for linking examples and demonstrations, i.e., the entry for examples and demonstrations is put into text flow. Self-test is given in the bottom of unit, after test explanation. In Figure 4, a pop-up example window is also layed on the screen to give an though idea. Figure 4 4 A typical layout of the KC unit Modules for Demonstration and Self-test In Figure 1, four lists are indicated. All the components of in these four lists are structured in modules. The reference module is made only with text, so it is implemented very straightforward. The example module is made of text plus table and image, but still similar to a test module. In the other side, the modules for demonstration and self-test are more complicated, they should provide interactive function and perform some processing and/or analysis tasks. According to their functions and contents, different techniques are used, such as Active X controller, Java Applet, Flash, etc [8]. A demonstration for image processing made by Active X Control is shown in Figure 5. It is a demonstration of Butterworth low-pass filtering. In this module, user can read a local image, process it and store the result in local machine. To get different result, user can interactively input the parameters for processing, as shown by the pop-up dialog box in the right of Figure 5. 555 Figure 5 A demonstration made by Active X Control A demonstration for image processing made by Java Applet is shown in Figure 6. It is a demonstration of Gradient operation. In this module, user can select one of provided images (as shown in low-left of Figure 6), select one of gradient detectors and its direction (the configuration of the detector is in the middle), and get thus a processed edge map (as shown in low-right of Figure 6). Figure 6 A demonstration made by Java Applet A demonstration for image processing made by Flash is shown in Figure 7. It is a demonstration of polygonal approximation of irregular object. Given an object at the start, this object will be superimposed on a lattice net, a polygonal resemblance is then obtained. Figure 7 A demonstration made by Flash Self-test module is also a module made by Flash. Each unit is composed of a question-answer pair. Excerpt showing the exercise problem, it has the functions of selecting code for problem solution, offering hint and providing explanatory answer. In addition, a statistic for number of solved problems is also counted. 556 Figure 8 5 A typical self-test screen layout made by Flash Conclusions In this paper, the general designing considerations, which are very important for the Web course development, are first discussed, the structure and realization of a particular Web course is then presented in details. Some components of this Web course have been partially used in the course conducted last year [9]. In a recent study about Web course structure, a hierarchical hyper concept map (HHCM) has been proposed [4]. It consists of an aggregation of the navigation map, the concept map and hypermedia document. Though different names are used, our proposed method and HHCM method share the same properties of combining the concept structure and navigation tools with different content representations. They have both the advantages of providing flexible access ability and reducing disorientation and cognitive overload. A Web course consists of a collection of different functional modules. Using various styles of learning would increase the study performance. Take this factor into consideration, totally 60 KC units, 91 examples, 36 demonstrations and 219 self-test units have been developed for the course of "Fundamentals of Image Processing and Analysis". In average, there are 1.5 examples and more than 3 self-test units for each KC unit. This has made this Web course a suitable choice for self-learning. References [1] Ahluwalia A K, Jonker P P, Young I T. An interactive image processing course for the Web. Proc. 1st International Conference on Image and Graphics, Y.J. Zhang ed., 589~593, 2000. 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