Asymmetric collaboration: Enabling a shared workspace through augmented and virtual realities

This dissertation presents a new paradigm of human to human Asymmetric Collaboration where the participants seamlessly collaborate in parallel virtual and real worlds. Current tele-collaboration systems deal only with collaboration purely in the real or the virtual worlds. The use of a combination of virtual and real worlds allows us to leverage the advantages from both the worlds. We present a heterogeneous distributed system that enables people in geographically separate locations to share a common workspace.; The real world user's perception is enhanced by augmenting information that is not part of the natural environment. Thus the Augmented Reality (AR) offers the user an intuitive and natural way to assimilate information and interact with the real world. A key challenge to the augmentation is determining precisely where to display the information by tracking the object to be annotated. Use of natural fiducials is not a robust option for a generic AR tracking. We propose an innovative hierarchical artificial fiducial with a multi-ring design. An experimental prototype, implemented with infrared LED's, demonstrates the suitability of the design for robust wide area tracking in adverse light conditions.; The overlay of 3D information requires the knowledge of the camera intrinsic parameters. Besides AR, camera calibration is an important step in 3D reconstruction of scenes. Many natural and man made objects are circular and form good candidates as calibration objects. A circular calibration pattern can be easily and accurately created. We present a new linear calibration algorithm to estimate the intrinsic camera parameters using at least three images of concentric circles of unknown radii. The calibration algorithm has the advantage of not requiring any measurements of the scene or the homography between the images. Moreover the proposed multi-ring artificial fiducials can be exploited for camera calibration.; In the virtual world, object manipulation defines the user experience. Precise manipulation of virtual objects is still difficult. The lack of haptic feedback is especially debilitating as knowledge on how to manipulate objects can no longer be stored in the world. To overcome this problem we propose the novel notion of Smart Objects that are aware of their interaction with the user and other objects. Smart Objects capture the essential handling cues and presents the information to the user in an intuitive way. They are tightly integrated with physics based collision detection which drives their behavior.