What Can Machine Vision Do For You ?

the widespread introduction of things and environments that see. However, reaping the benefits of ubiquitous perception will require consideration of human abilities and social needs as an integral part of system design. Research in human-computer interaction (HCI) has developed cognitive theories, design methods, and software tools for building useful and usable systems. Scientific results and empirical studies have led to sound principles such as that of direct manipulation. For nearly two decades, however, direct manipulation has been instantiated in the form of the “electronic desktop metaphor,” jeopardizing the directness and the affordance of the physical world. Recent efforts in HCI seek a seamless bridge between physical and electronic bits. Wellner’s Digital Desk [12] and Fitzmaurice’s Bricks [6] illustrate this trend. In the Digital Desk, physical office tools such as paper sheets and erasers are augmented with computation using video projection and machine vision. The Bricks allow direct manipulation of electronic objects using Lego-like physical artifacts as handles to control the virtual world. The Digital Desk and other graspable iconic systems inspired from the Bricks have demonstrated the benefits of mixing physical and virtual entities. However, because they use naive machine vision techniques, their contribution cannot be tested in real-life conditions. Advances in machine vision provide an opportunity to make these new paradigms effective.