Thesis (M.S.)--University of Alabama at Birmingham, 2006. / Description based on contents viewed June 26, 2007; title from title screen. Includes bibliographical references.

Indiana University-Purdue University Indianapolis (IUPUI) / A new method for capturing 3D video from a single imager and lens is introduced in this research. The benefit of this method is that it does not have the calibration and alignment issues associated with binocular 3D video cameras, and allows for a less expensive overall system. The digital imaging technique Depth from Defocus (DfD) has been successfully used in still camera imaging to develop a depth map associated with the image. However, DfD has not been applied in real-time video so far since the focus mechanisms are too slow to produce real-time results. This new research result shows that a Microfluidic lens is capable of the required focal length changes at 2x video frame rate, due to the electrostatic control of the focus. During the processing, two focus settings per output frame are captured using this lens combined with a broadcast video camera prototype. We show that the DfD technique using Bayesian Markov Random Field optimization can produce a valid depth map.

This dissertation investigated the impact of active stereoscopic 3-dimensional (3D) imagery equipment and individual differences in visuo-spatial working memory (VSWM) capacity on retention of a set of similar, novel objects (i.e., armored military vehicles). Seventy-one participants were assessed on their visuo-spatial working memory using the Visual Patterns Test (Della Sala, Gray, Baddeley, & Wilson, 1997). They were then assigned to one of four different conditions (3D high VSWM, 3D low VSWM, 2D high VSWM, 2D low VSWM) based upon their visuo-spatial working memory. Participants were then trained to identify military vehicles using a simulation that presented the training stimuli in one of two dimensionalities, i.e. two dimensional (2D) or active stereoscopic three-dimensional (3D). Testing consisted of a vehicle memory training assessment, which challenged participants to choose the correct components of each vehicle immediately after studying; a measure of retention for military vehicles which asked participants to categorize the alliance and identify previously studied vehicles; and a transfer measure using video footage of actual military vehicles. The latter measures depicted military vehicles in an array of combat situations, and participants were asked to decide on whether or not to shoot each vehicle, as well as identify the vehicles. Testing occurred immediately after training. The moderating, as well as main effects, of VSWM were assessed. The mediating/moderating effects of several experiential factors were measured as well, including: immersion, presence, engagement, flow state, and technology acceptance. Findings indicate that perceptions of the simulation experience and VSWM are strong positive predictors of performance, while 3D was not predictive, and in some instances, significantly worse than the 2D condition. These findings indicate that individual differences in visual memory and user experiences during the SBT both are predictive factors in memory tasks iv for confusable objects. The SBT designed in this study also led to robust prediction of training outcomes on the final transfer task.

In breast cancer assessment, tissue removed during biopsy or surgery is sent to a pathology lab for analysis. To achieve high sensitivity for detecting disease, the diagnostic gold standard requires submission of a substantial portion of the resected specimen, which results in a labor and time-intensive process to obtain a diagnosis. There is an unmet need to identify regions of diagnostic interest in breast tissue samples to increase the efficiency of the clinical pathology workflow. Optical coherence tomography (OCT), a noninvasive imaging modality capable of depth-resolved, high-resolution, and in vivo imaging of tissue at large fields of view, enables effective assessment of this tissue. However, there is a two-fold problem: the large size of resected tissue to be imaged within clinical time constraints, and the high density of multi-dimensional OCT image data. An approach that enables comprehensive imaging by reducing both imaging time and data density is compressed sensing (CS), a theory that enables undersampling far below the Nyquist sampling rate and guarantees high accuracy image recovery. Therefore, the objective of this work is to demonstrate that compressed sensing techniques can be applied to OCT imaging to revise current optical hardware and improve the efficiency of image acquisition. CS-OCT has high potential for significantly altering the presently established workflow for breast cancer assessment. In this work, we prove that current OCT systems require further reduction of data sampling rate, to enable effective integration of the systems into the clinical pathology workflow. In addition, we identify challenges associated with the matching of OCT and histologic data that may be important to consider in the context of in vivo imaging. Further, we demonstrate the application of a novel and improved compressed sensing algorithm capable of reconstructing OCT volumes from highly undersampled imaging data. We show that these reconstructions preserve high spatial resolution and key image features, and we illustrate its improved performance over traditional reconstruction methods. Lastly, we integrate our compressed sensing techniques to physical OCT hardware. We demonstrate a pilot OCT system that integrates efficient undersampling schemes with subsequently successful 3-D image reconstructions. We evaluate acquisition patterns that take advantage of the typical forward and backward scan cycle of OCT systems to accomplish native subsampling of target data to varying degrees of compression. Using our CS-OCT algorithm, we successfully reconstruct OCT image volumes and demonstrate qualitative and quantitative preservation of image quality down to compression levels of 5% of total data.

Thesis (M. Tech. Design technology) -- Central University of Technology, Free State, 2011 / This dissertation outlines a procedural scanning process using the portable ZCorporation ZScanner® 700 and provides an overview of the developments surrounding 3D scanning technologies; specifically their application for archiving Cultural Heritage sites and projects. The procedural scanning process is structured around the identification of 3D data recording variables applicable to the digital archiving of an art museum’s collection of sculptures. The outlining of a procedural 3D scanning environment supports the developing technology of 3D digital archiving in view of artefact preservation and interactive digital accessibility. Presented in this paper are several case studies that record 3D scanning variables such as texture, scale, surface detail, light and data conversion applicable to varied sculptural surfaces and form. Emphasis is placed on the procedural documentation and the anomalies associated with the physical object, equipment used, and the scanning environment. In support of the above, the Cultural Heritage projects that are analyzed prove that 3D portable scanning could provide digital longevity and access to previously inaccessible arenas for a diverse range of digital data archiving infrastructures. The development of 3D data acquisition via scanning, CAD modelling and 2D to 3D data file conversion technologies as well as the aesthetic effect and standards of digital archiving in terms of the artwork – viewer relationship and international practices or criterions of 3D digitizing are analysed. These projects indicate the significant use of optical 3D scanning techniques and their employ on renowned historical artefacts thus emphasizing their importance, safety and effectiveness. The aim with this research is to establish that the innovation and future implications of 3D scanning could be instrumental to future technological advancement in an interdisciplinary capacity to further data capture and processing in various Cultural Heritage diagnostic applications.

published_or_final_version / Civil Engineering / Master / Master of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Geography / Master / Master of Philosophy