This thesis presents the development of a set of novel graphical tools Known as 'virtual primitives' that allow the user of a stereoscopic telepresence system to actively and intuitively model features in a remote environment. The virtual primitives provide visual feedback during the model creating process in the form of a dynamic wireframe of the primitive overlaid and registered with the real object. The operator can immediately see the effect of his decisions and if necessary make minor corrections to improve the fit of the primitive during its generation. Virtual primitives are a generic augmented reality (AR) tool and their applications extend past the modelling of a workspace for telerobot operation to other remote tasks such as visual inspection, surveying and collaborative design. An AR system has been developed and integrated with the existing Surrey Telepresence System. The graphical overlays are generated using virtual reality software and combined with the video images. To achieve a one-to-one correspondence between the real and virtual worlds the AR system is calibrated using a simple pinhole camera model and standard calibration algorithm. An average RMS registration error between the video and graphical images of less than one framegrabber pixel is achieved. An assessment of a virtual pointer confirms that this level of accuracy is acceptable for use with the virtual primitives. The concept of the virtual primitives has been evaluated in an experiment to model three test objects. The results show that using a virtual primitive was superior in accuracy and task completion time to using a pointer alone. Finally, a case study on the remote inspection of sewers demonstrates the advantages of virtual primitives in a real application. It confirms that the use of virtual primitives significantly reduces the subjective nature of the task, offers an increase in precision by an order of magnitude over conventional inspection methods, and provides additional useful data on the characteristics of the sewer features not previously available.

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Bibliography: leaves 71-76. / by Scott Stevens Fisher. / M.S.V.S.

In order to realize the advanced graphics rendering algorithms which tends to become more complex and flexible, more and more graphics processor units (GPU) include a micro-processor-like core to support the programmable shading capability. However, since the number of cycles spent in the fragment shader in programmable GPU will vary with different applications, the hardware implementation of the remaining fixed function of the graphics rendering flow becomes not trivial because the suitable target throughput is hard to set. In addition, the data transfer between the shader processor and other hardware fixed-function modules will also represent a big overhead. Therefore, this thesis focuses on realizing the rasterization, which is a very important fixed rendering function, and proposes a pure-software solution that can be executed by the shader processor. The pure-software rasterization requires 98 cycles in setup-stage, and an average of 13 cycles per pixel in interpolation-stage. To further accelerate this rasterization, this thesis also proposes an hardware-software codesign which uses a embedded scan-conversion unit to cooperate with the shader processor. This unit costs about 8.5K gates, which occupies only 1.7% of the entire GPU, but can help reduce more than 30% cycles compared with the pure-software approach in the test-benches used in this thesis. The other contribution of this thesis is to implement the stereoscopic graphic rendering function. To provide stereoscopic effect, the graphic rendering system has to run the entire rendering flow for additional passes to generate the results from different views. However, this thesis will embed an additional code in the fragement shader to adjust the x-coordinate position generated by vertex shader to avoid the additional running pass of the vertex shader.

The research involves the creation of an interactive installation showcasing the dynamic nature of human visual observation of a still photograph. Using an eye tracker as an input device, the data collected is used to create a photographic collage in stereoscopic 3D. The installation is artistically inspired by selected photographic works of artists David Hockney, Maurizio Galimberti, Joyce Neimanas and Cubist painters especially Picasso. One of the key factors in their work that is adapted in this research, is the representation of the way eyes search points of interest demonstrated in what they painted/photographed. The installation will demonstrate an expressive representation of the viewers' experience of looking at a photograph. This will be achieved by applying certain manipulations of the photograph based on the input obtained from the viewer using an eye tracker. The eye tracker collects information about the location and number of instances of where the viewer is when observing a photograph. This is fed into software that processes the data and determines the location and the size of the area of the photograph and amount of the manipulation to be applied to that area. These two constitute the artistic rules that are used to create the end product the photo collage. The individual pieces of the collage will be arranged in a virtual 3D model by the artist and will be projected in stereoscopic 3D. The development of this installation progressed through multiple case studies and optimization based on ease of use, cost and availability of resources. This process is intended to be a framework for artists working in interactive visual media.

Thesis (M.A.)--University of Wisconsin--Madison, 1967. / Description based on print version record. Includes bibliographical references.

No description available.

Real-time tracking and object recognition is a large field with many possible applications. In this thesis we present a technical demo of a stereoscopic tracking system using artificial neural networks (ANN) and also an overview of the entire system, and its core functions. We have implemented a system able of tracking an object in real time at 60 frames per second. Using stereo matching we can extract the object coordinates in each camera, and calculate a distance estimate from the cameras to the object. The system is developed around the Xilinx ZC-706 evaluation board featuring a Zynq XC7Z045 SoC. Performance critical functions are implemented in the FPGA fabric. A dual-core ARM processor, integrated on the chip, is used for support and communication with an external PC. The system runs at moderate clock speeds to decrease power consumption and provide headroom for higher resolutions. A toolbox has been developed for prototyping and the aim has been to run the system with a one-push-button approach. The system can be taught to track any kind of object using an eight bit 32 × 16 pixel pattern generated by the user. The system is controlled over Ethernet from a regular workstation PC, which enables it to be very user-friendly.

It is commonly known that stereopsis is the primary way for humans to perceive depth. Although, with one eye, we can still interact very well with our environment and do very highly skillful tasks by using other visual cues such as occlusion and motion, the resultant e ect of the absence of stereopsis is that the relative depth information between objects is essentially lost (Frisby,1979). While humans fuse the images seen by the left and right eyes in a seemingly easy way, the major problem - the correspondence of features - that needs to be solved in all binocular stereo systems of machine vision is not trivial. In this thesis, line segments and corners are chosen to be the features to be matched because they typically occur at object boundaries, surface discontinuities, and across surface markings. Polygonal regions are also selected since they are known to be well-configured and are, very often, associated with salient structures in the image. The use of these high level features, although helping to diminish matching ambiguities, does not completely resolve the matching problem when the scene contains repetitive structures. The spatial relationships between the feature matching pairs enforced in the stereo matching process, as proposed in this thesis, are found to provide even stronger support for correct feature matching pairs and, as a result, incorrect matching pairs can be largely eliminated. Getting global and salient 3D structures has been an important prerequisite for environmental modelling and understanding. While research on postprocessing the 3D information obtained from stereo has been attempted (Ayache and Faugeras, 1991), the strategy presented in this thesis for retrieving salient 3D descriptions is propagating the prominent information extracted from the 2D images to the 3D scene. Thus, the matching of two prominent 2D polygonal regions yields a prominent 3D region, and the inter-relation between two 2D region matching pairs is passed on and taken as a relationship between two 3D regions. Humans, when observing and interacting with the environment do not confine themselves to the observation and then the analysis of a single image. Similarly stereopsis can be vastly improved with the introduction of additional stereo image pairs. Eye, head, and body movements provide essential mobility for an active change of viewpoints, the disocclusion of occluded objects, the avoidance of obstacles, and the performance of any necessary tasks on hand. This thesis presents a mobile stereo vision system that has its eye movements provided by a binocular head support and stepper motors, and its body movements provided by a mobile platform, the Labmate. With a viewer centred coordinate system proposed in this thesis the computation of the 3D information observed at each individual viewpoint, the merging of the 3D in formation at consecutive viewpoints for environmental reconstruction, and strategies for movement control are discussed in detail.

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 112-119). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR19668

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 82-85). Also available in electronic version.