A Wavelet Transform Applet for Interactive Learning

In recent years, new forms and techniques of teaching have appeared, based on the Internet and on multimedia applications. In the teleteaching Project Virtual University of the Upper Rhine Valley (VIROR), multimedia simulations and animations complement traditional teaching material. Lecturers use Java applets in their courses to explain complex structures. These are then stored in a multimedia database to enable asynchronous learning. The wavelet transform has become the most interesting new algorithm for still image compression. Yet, there are many parameters within a wavelet analysis and synthesis: choice of the wavelet filter bank, decomposition strategy, image boundary policy, quantization threshold, etc. We consider the wavelet transform to be a typical example of a complex, hard-to-understand algorithm that needs illustration by interactive multimedia. In this article, we present the didactic background and the implementation of a sample applet on the discrete wavelet transform, as taught in our multimedia course