Sensor planning for novel view generation by camera networks

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2006.Includes bibliographical references (p. 75-78).This document describes a system for generating novel views of an indoor visual scene by gathering successive 2D images from a set of independent networked robotic cameras. Specifically, the robotic cameras work to seek out texture and geometric information needed to generate the specified synthetic view or views, aiming to-with each successive camera move-increase confidence in the estimates of the pixel intensities in the novel view(s). This system lays the groundwork for future explorations in multi-camera video recording for electroholography and image-based rendering.by James Barabas.S.M

Measuring visual performance with holographic and other 3D television technologies

Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (pages 89-96).We are surrounded by visual reproductions: computer screens, photographs, televisions, and countless other technologies allow us to perceive objects and scenes that are not physically in-front of us. All existing technologies that reproduce images perform engineering tradeoffs that provide the viewer with some subset of the visual information that would be available in person, in exchange for cost, convenience, or practicality. For many viewing tasks, incomplete reproductions go unnoticed. This dissertation provides a set of findings that illuminate the value of binocular disparity, and ocular focus information that can be provided by some three-dimensional display technologies. These findings include new experimental methods, as well as results, for conducting evaluations of current and future display technologies. Methodologies were validated on an implementation of digital holographic television, an image capture and reproduction system for visual telepresence. The holographic television system, allows viewers to observe, in real-time, a remote 3D scene, through a display that preserves focus (individual objects can be brought into optical focus at the expense of others), and horizontal motion parallax (depth and other geometry of objects appears natural over a range of head movement). Holographic television can also emulate other precursor 2D and 3D display technologies. This capability was used to validate the evaluation methodologies (meta-evaluation) by comparing visual performance on simulations of conventional displays to results of past studies by other researchers.by James Barabas.Ph. D

A Feedback-Controlled Interface for Treadmill Locomotion in Virtual Environments

Virtual environments (VEs) allow safe, repeatable, and controlled evaluations of obstacle avoidance and navigation performance of people with visual impairments using visual aids. Proper simulation of mobility in a VE requires an interface, which allows subjects to set their walking pace. Using conventional treadmills, the subject can change their walking speed by pushing the tread with their feet, while leveraging handrails or ropes (self-propelled mode). We developed a feedback-controlled locomotion interface that allows the VE workstation to control the speed of the treadmill, based on the position of the user. The position and speed information is also used to implement automated safety measures, so that the treadmill can be halted in case of erratic behavior. We compared the feedback-controlled mode to the self-propelled mode by using speed-matching tasks (follow a moving object or match the speed of an independently moving scene) to measure the efficacy of each mode in maintaining constant subject position, subject control of the treadmill, and subject pulse rates. Additionally, we measured the perception of speed in the VE on each mode. The feedback-controlled mode required less physical exertion than self-propelled. The average position of subjects on the feedbackcontrolled treadmill was always within a centimeter of the desired position. There was a smaller standard deviation in subject position when using the self-propelled mode than when using the feedback-controlled mode, but the difference averaged less than six centimeters across all subjects walking at a constant speed. Although all subjects underestimated the speed of an independently moving scene a

Real-time shader rendering of holographic stereograms

Horizontal-parallax-only holographic stereograms of nearly SDTV resolution (336 pixels by 440 lines by 96 views) of textured and normal-mapped models (500 polygons) are rendered at interactive rates (10 frames/second) on a single dual-head commodity graphics processor for use on MIT’s third-generation electro-holographic display. The holographic fringe pattern is computed by a diffraction specific holographic stereogram algorithm designed for efficient parallelized vector implementation using OpenGL and Cg vertex/fragment shaders. The algorithm concentrates on lightfield reconstruction by holographic fringes rather than the computation of the interferometric process of creating the holographic fringes