Image processing techniques for mixed reality and biometry

2013 - 2014This thesis work is focused on two applicative fields of image processing research, which, for different reasons, have become particularly active in the last decade: Mixed Reality and Biometry. Though the image processing techniques involved in these two research areas are often different, they share the key objective of recognizing salient features typically captured through imaging devices. Enabling technologies for augmented/mixed reality have been improved and refined throughout the last years and more recently they seems to have finally passed the demo stage to becoming ready for practical industrial and commercial applications. To this regard, a crucial role will likely be played by the new generation of smartphones and tablets, equipped with an arsenal of sensors connections and enough processing power for becoming the most portable and affordable AR platform ever. Within this context, techniques like gesture recognition by means of simple, light and robust capturing hardware and advanced computer vision techniques may play an important role in providing a natural and robust way to control software applications and to enhance onthe- field operational capabilities. The research described in this thesis is targeted toward advanced visualization and interaction strategies aimed to improve the operative range and robustness of mixed reality applications, particularly for demanding industrial environments... [edited by Author]XIII n.s

Physical Interaction Concepts for Knowledge Work Practices

The majority of workplaces in developed countries concern knowledge work. Accordingly, the IT industry and research made great efforts for many years to support knowledge workers -- and indeed, computer-based information workplaces have come of age. Nevertheless, knowledge work in the physical world has still quite a number of unique advantages, and the integration of physical and digital knowledge work leaves a lot to be desired. The present thesis aims at reducing these deficiencies; thereby, it leverages late technology trends, in particular interactive tabletops and resizable hand-held displays. We start from the observation that knowledge workers develop highly efficient practices, skills, and dexterity of working with physical objects in the real world, whether content-unrelated (coffee mugs, stationery etc.) or content-related (books, notepads etc.). Among the latter, paper-based objects -- the notorious analog information bearers -- represent by far the most relevant (super-) category. We discern two kinds of practices: collective practices concern the arrangement of objects with respect to other objects and the desk, while specific practices operate on individual objects and usually alter them. The former are mainly employed for an effective management of the physical desktop workspace -- e.g., everyday objects are frequently moved on tables to optimize the desk as a workplace -- or an effective organization of paper-based documents on the desktop -- e.g., stacking, fanning out, sorting etc. The latter concern the specific manipulation of physical objects related to the task at hand, i.e. knowledge work. Widespread assimilated practices concern not only writing on, annotating, or spatially arranging paper documents but also sophisticated manipulations -- such as flipping, folding, bending, etc. Compared to the wealth of such well-established practices in the real world, those for digital knowledge work are bound by the indirection imposed by mouse and keyboard input, where the mouse provided such a great advancement that researchers were seduced to calling its use "direct manipulation". In this light, the goal of this thesis can be rephrased as exploring novel interaction concepts for knowledge workers that i) exploit the flexible and direct manipulation potential of physical objects (as present in the real world) for more intuitive and expressive interaction with digital content, and ii) improve the integration of the physical and digital knowledge workplace. Thereby, two directions of research are pursued. Firstly, the thesis investigates the collective practices executed on the desks of knowledge workers, thereby discerning content-related (more precisely, paper-based documents) and content-unrelated object -- this part is coined as table-centric approaches and leverages the technology of interactive tabletops. Secondly, the thesis looks at specific practices executed on paper, obviously concentrating on knowledge related tasks due to the specific role of paper -- this part is coined as paper-centric approaches and leverages the affordances of paper-like displays, more precisely of resizable i.e. rollable and foldable displays. The table-centric approach leads to the challenge of blending interactive tabletop technology with the established use of physical desktop workspaces. We first conduct an exploratory user study to investigate behavioral and usage patterns of interaction with both physical and digital documents on tabletop surfaces while performing tasks such as grouping and browsing. Based on results of the study, we contribute two sets of interaction and visualization concepts -- coined as PaperTop and ObjecTop -- that concern specific paper based practices and collective practices, respectively. Their efficiency and effectiveness are evaluated in a series of user studies. As mentioned, the paper-centric perspective leverages late ultra-thin resizable display technology. We contribute two sets of novel interaction concepts again -- coined as FoldMe and Xpaaand -- that respond to the design space of dual-sided foldable and of rollout displays, respectively. In their design, we leverage the physical act of resizing not "just" for adjusting the screen real estate but also for interactively performing operations. Initial user studies show a great potential for interaction with digital contents, i.e. for knowledge work

Visualizing and Understanding Tectonism and Volcanism on Earth and Other Terrestrial Bodies

This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of the planetary surface, including long volcanic island chains, deep ocean basins, and plate boundary triple junctions. Better understanding of these processes by visualization and numerical modeling is one of the primary goals of this study. In the geospatial analysis lab at ODU, our research methodology starts with the creation of visualizations for teaching. These include Google Earth-based virtual field explorations enhanced with digitized specimens and emergent geological and geophysical cross sections. We test these in classes with IRB compliance and sometimes this leads to the discovery of tectonic research questions which we then explore. Settings studied in this investigation are Tonga Trench in the western Pacific Ocean, Artemis on Venus, the Hawaiian-Emperor seamount chain, and the Azores triple junction. Some of these cases pose specific geophysical problems that were selected for further study. The Tonga Trench is a subduction zone that includes trench rollback and opening of a marginal basin—the Lau Basin. The rollback process is difficult to imagine, and therefore we created a set of instructional resources using COLLADA models and the Google Earth Application Programming Interface (API). Animated models for the assessments tests and exploration of different initiations of the subduction process led to a new alternative hypothesis for rollback. Virtual field explorations required the development of new interface features for the Google Earth API. All these instructional materials were combined into modular multi-user virtual field trip experiences and were subject to IRB-compliant evaluation of learning outcomes. Animated COLLADA models for the Hawaii Islands and Emperor Seamounts helped explain the origin and time progression of the island chain. From seismic data, a three-dimensional reconstruction of the Hawaiian mantle plume was created raising the question of the horizontal advection of the plume conduit in the mantle and its correlation with the change in trend of the islands. The Hawaiian–Emperor chain on Earth is spread out as the Pacific plate is moving over the Hawaiian mantle plume. On Venus, however, the Artemis structure was able to grow to super-plume size due to the absence of plate motion. For Venus, visualization was done on a much larger scale, including cross sections of the whole plate showing large plume structures, and Magellan SARS imagery of surface features. In the Azores triple junction, dispersion of plume material is influenced by plate boundary geometry, creating anomalies in seafloor geophysical data for several hundred kilometers away from the plume center. To explore the interaction between a mantle plume and a plate boundary triple junction, a series of three dimensional finite element numerical models was calculated. A parameter space investigation changed the location of the plume conduit and its volume flux, as well as the treatment of viscosity. Flow patterns, dynamical topography, relative crustal thickness variations and waist width scaling relationships resulting from these calculations give valuable insight into the importance of triple junction configuration in the dispersion of plume material