Hook and screen division based screen compression for the real-time multimedia transformation of e-learning system

Abstract

Real-time multimedia transfer is critical for E-learning application. Efficient compression technology should exist to transfer the teaching white board from the main classroom to the student's PC or the distance classroom, along the limited network bandwidth. We assume that the teachers use MS PowerPoint or MS Word in the main classroom for teaching, and we record the screen with our compression technology and transfer the screen video to the distance classroom or students' PCs, the compression uses hook technology to trace the changed area of the screen and divided the screen into 16 small rectangles, and it selectively compressed the changed area of the screen with lossless and lossy compression methods, and use a long motion compensation history buffer to further reduce the time redundancy. The compression method can get a pretty high compression ratio and very good quality of the text and simple icons that are more important; besides, the CPU utilization is also pretty low. © Springer-Verlag 2004.