Automated Registration of High Resolution Images from Slide Presentation and Whiteboard Handwriting via a Video Camera

A PowerPoint© (PPT) slide presentation and a whiteboard handwriting capture system, when used together, could provide a better means to present a lecture in a classroom and later to deliver more effective e-lectures for off-campus students. When the PPT slides are projected on the whiteboard where the instructor annotates, modifies, or expands the PPT presentation, geometrically registering high-resolution images from the two sources yields high quality digital presentations. Since the two sources do not share the same materials, one with printing notes and the other with handwriting notes, we use a low-cost digital camera as a bridge to align the two sources. We present a hybrid registration approach to align the PPT and handwriting images. We use domain knowledge in a classroom presentation (i.e., the illumination of the slide projection, the timing information for both slide changes and handwriting page creation) to align the camera views with the digital slides and to extract handwriting contents from clustered video scenes. We propose a coarse-to-fine content matching method to register handwriting contents captured by the video camera and the whiteboard capture system. Experimental results are presented to validate our approach.