Improved background removal through polarisation in vision-based tabletop interface

This paper presents a novel method of enhancing computer assisted motor rehabilitation for brain injury patients by detailing a method of overcoming a significant technical constraint. The focus of our system is three dimen- sional(3D) tracking of upper limb movements on a horizontal tabletop system. We describe a new horizontal table- top system that utilises real-time stereo vision for 3D tracking of user interaction in the workspace. An overview of existing background removal techniques is presented, and their strengths and weaknesses discussed. We then present a novel approach that utilises polarisation of light for background removal. The system uses an LCD panel for the display device, which achieves a more portable system, and also allows for total removal of screen interference by utilising the polarising nature of LCD technology. Initial testing of this approach has proved highly successful. Key benefits are outlined.