In this study, Computer Assisted Learning (CAL) is seen through a collection of experimentation in a course software package used to understand the concepts of a particular subject. Digital image processing is one of the computer science subjects that is compulsory for computer science students majoring in artificial intelligence in the National Defence University of Malaysia. To enhance Digital Image Processing subject, Matlab Graphical User Interface (GUI) has been used as a tool for CAL. The simulation in GUI focuses on Morphology operation topic in Digital Image Processing subject. Four main techniques can be executed on the layout of the GUI which shows the effect of the techniques when applied on a particular image. The preliminary findings show that this Matlab GUI proved to be an excellent tool for CAL environment and it is user friendly due to its convenience to the students.