Detecting Handwritten Annotation by Synchronization of Lecture Slides and Videos

摘要

Pervasiveness of streaming media and the Internet have led to the widespread popularity of e-Learning, necessitating an effective means of retrieving lecture videos conveniently. Teachers usually illustrate major pedagogical concepts by taking a considerable amount of time in explanation with handwritten annotations. This study presents a handwritten annotation detection method for e-Learning video streams to facilitate retrieval of annotated slides and increase students' learning efficiency. Although many visual content-based retrieval methods have been proposed for lecture videos in terms of slide, topic, and text, few are specifically designed for handwritten annotations. Moreover, most existing annotation retrieval methods are developed for chalkboard presentation rather than electronic slides. Therefore, the objective of this study is to develop a simple yet effective annotation detection method for lecture videos using slide presentation. The proposed method consists of three stages, slide keyframe extraction, slide/video synchronization, and handwritten annotation detection. Experimental results demonstrate the feasibility of the proposed method.