We propose a system that allows multiple groups of users at remote locations to naturally share a 3D image of real objects. All users can interactively observe a 3D stereoscopic image without distortion from their own viewpoints. The system basically consists of a combination of systems: imaging and display. The imaging system captures the real object's images from certain number of viewpoints which are used to generate stereoscopic images from arbitrary viewpoints based on an image-based rendering technique implemented on GPU. The display system interactively generates a 3D virtual image of the real object based on the IllusionHole technique. Users at one place just put the real object on their imaging system to capture a set of its images from sparse viewpoints around it; other groups of multiple users at remote places connected by networks observe its virtual image from arbitrary viewpoints on their display systems.

Multi-display environments compose displays that can be at different locations from and different angles to the user; as a result, it can become very difficult to manage windows, read text, and manipulate objects. We investigate the idea of perspective as a way to solve these problems in multi-display environments. We first identify basic display and control factors that are affected by perspective, such as visibility, fracture, and sharing. We then present the design and implementation of E-conic, a multi-display multi-user environment that uses location data about displays and users to dynamically correct perspective. We carried out a controlled experiment to test the benefits of perspective correction in basic interaction tasks like targeting, steering, aligning, pattern-matching and reading. Our results show that perspective correction significantly and substantially improves user performance in all these tasks.

This paper discusses the use of common source MOS transistors operating in the linear region to create four-quadrant multipliers. Analyses of two different multipliers based on this concept are presented and verified through SPICE simulations. The second circuit is shown to have low distortion, low sensitivity to mismatch, and good high frequency performance.>