Spatial augmented reality is a particular kind of augmented reality technique that uses projector to blend the real objects with virtual contents. Coincidentally, as a means of 3D shape measurement, structured light illumination makes use of projector as part of its system as well. It uses the projector to generate important clues to establish the correspondence between the 2D image coordinate system and the 3D world coordinate system. So it is appealing to build a system that can carry out the functionalities of both spatial augmented reality and structured light illumination. In this dissertation, we present all the hardware platforms we developed and their related applications in spatial augmented reality and structured light illumination. Firstly, it is a dual-projector structured light 3D scanning system that has two synchronized projectors operate simultaneously, consequently it outperforms the traditional structured light 3D scanning system which only include one projector in terms of the quality of 3D reconstructions. Secondly, we introduce a modified dual-projector structured light 3D scanning system aiming at detecting and solving the multi-path interference. Thirdly, we propose an augmented reality face paint system which detects human face in a scene and paints the face with any favorite colors by projection. Additionally, the system incorporates a second camera to realize the 3D space position tracking by exploiting the principle of structured light illumination. At last, a structured light 3D scanning system with its own built-in machine vision camera is presented as the future work. So far the standalone camera has been completed from the a bare CMOS sensor. With this customized camera, we can achieve high dynamic range imaging and better synchronization between the camera and projector. But the full-blown system that includes HDMI transmitter, structured light pattern generator and synchronization logic has yet to be done due to the lack of a well designed high speed PCB.

Structured Light Imaging (SLI) is a means of digital reconstruction, or Three-Dimensional (3D) scanning, and has uses that span many disciplines. A projector, camera and Personal Computer (PC) are required to perform such 3D scans. Slight variances in synchronization between these three devices can cause malfunctions in the process due to the limitations of PC graphics processors as real-time systems. Previous work used a Field Programmable Gate Array (FPGA) to both drive the projector and trigger the camera, eliminating these timing issues, but still needing an external camera. This thesis proposes the incorporation of the camera with the FPGA SLI controller by means of a custom printed circuit board (PCB) design. Featuring a high speed image sensor as well as High Definition Multimedia Interface (HDMI) input and output, this PCB enables the FPGA to perform SLI scans as well as pass through HDMI video to the projector for Spatial Augmented Reality (SAR) purposes. Minimizing ripple noise on the power supply by means of effective circuit design and PCB layout, realizes a compact and cost effective machine vision sensing solution.

This production journal acts as a public record of the journey to produce my MFA thesis film, Mirror, Mirror Perfected. Operating as a folktale, Mirror, Mirror Perfected is a hybrid speculative suspense film looking at our intersect with social media through the eyes of a young dancer in a near-future world. The journal includes notes from research during my time at the University of Iowa in New Media Studies, Sociology and Performance Studies. I explore how, for instance, the Narcissus myth attempts to influence my world through the liminality of instant gratification, technology, and the fragmentation of identity. The journal also accounts for the conceptual, personal, and practical considerations for the development of Mirror, Mirror Perfected since 2012.

Quantifying human posture and range of motion remains challenging due to the need for specific technologies, time for data collection and analysis, and space requirements. The demand for affordable and accessible human body position measurement requires alternative methods that cost less, are portable, and provide similar accuracy to expensive multi-camera systems. This thesis developed and evaluated a novel augmented reality mobile app for human posture measurement to bring marker-based body segment measurement to the point of patient contact. The augmented reality app provides live video of the person being measured, AprilTag2 fiducial markers locations in the video, processes marker data, and calculates angles and distances between markers. Results demonstrated that the mobile app can identify, track, and measure angles and distances between AprilTag2 markers attached to a human body in real-time with millimetre accuracy, thereby allowing researchers and clinicians to quantify posture measurements anywhere, at anytime.

The purpose of this study has been to investigate if the Pervasive GameFlow Model is suitable for evaluating Player Experience in Augmented Reality games. The work has described a definition of Augmented Reality, how it generally operates and reviewed common challenges when developing Augmented Reality applications. A prototype game has been developed, based on a previous concept of merging board games with computer games using Augmented Reality. After development, the game has been tested with a method based on the Pervasive GameFlow Model. Results showed the model to be suitable for future tests and evaluations, but did not produce data for evolving the game design. Generating such data would require execution of additional testing methods. / Syftet med denna studie har varit att undersöka om Pervasive GameFlow Modellen är lämplig för att utvärdera spelarupplevelse i Augmented Reality-spel. Arbetet har beskrivit en definition av Augmented Reality, hur det generellt fungerar och granskat vanliga utmaningar vid utveckling av Augmented Reality-applikationer. Ett prototypspel har utvecklats, baserat på ett tidigare koncept för att slå samman brädspel med datorspel med hjälp av Augmented Reality. Efter utveckling har spelet testats med en metod baserad på Pervasive GameFlow Modellen. Resultat visade att modellen var lämplig för framtida tester och utvärderingar, men producerade inte data för att utveckla speldesignen. Generering av sådan data skulle kräva utförande av ytterligare testmetoder.

Augmented Reality (AR) involves adding virtual content into real scenes. Scenes are viewed using a Head-Mounted Display or other display type. In order to place content into the user's view of a scene, the user's position and orientation relative to the scene, commonly referred to as their pose, must be determined accurately. This allows the objects to be placed in the correct positions and to remain there when the user moves or the scene changes. It is achieved by tracking the user in relation to their environment using a variety of technology. One technology which has proven to provide accurate results is computer vision. Computer vision involves a computer analysing images and achieving an understanding of them. This may be locating objects such as faces in the images, or in the case of AR, determining the pose of the user. One of the ultimate goals of AR systems is to be capable of operating under any condition. For example, a computer vision system must be robust under a range of different scene types, and under unpredictable environmental conditions due to variable illumination and weather. The majority of existing literature tests algorithms under the assumption of ideal or 'normal' imaging conditions. To ensure robustness under as many circumstances as possible it is also important to evaluate the systems under adverse conditions. This thesis seeks to analyse the effects that variable illumination has on computer vision algorithms. To enable this analysis, test data is required to isolate weather and illumination effects, without other factors such as changes in viewpoint that would bias the results. A new dataset is presented which also allows controlled viewpoint differences in the presence of weather and illumination changes. This is achieved by capturing video from a camera undergoing a repeatable motion sequence. Ground truth data is stored per frame allowing images from the same position under differing environmental conditions, to be easily extracted from the videos. An in depth analysis of six detection algorithms and five matching techniques demonstrates the impact that non-uniform illumination changes can have on vision algorithms. Specifically, shadows can degrade performance and reduce confidence in the system, decrease reliability, or even completely prevent successful operation. An investigation into approaches to improve performance yields techniques that can help reduce the impact of shadows. A novel algorithm is presented that merges reference data captured at different times, resulting in reference data with minimal shadow effects. This can significantly improve performance and reliability when operating on images containing shadow effects. These advances improve the robustness of computer vision systems and extend the range of conditions in which they can operate. This can increase the usefulness of the algorithms and the AR systems that employ them.

With increasing pressure to better manage the environment many government and private organisations are studying the relationships between social, economic and environmental factors to determine how they can best be optimised for increased sustainability. The analysis of such relationships are undertaken using computer-based Integrated Catchment Models (ICM). These models are capable of generating multiple scenarios depicting alternative land use alternatives at a variety of temporal and spatial scales, which present (potentially) better Triple-Bottom Line (TBL) outcomes than the prevailing situation. Dissemination of this data is (for the most part) reliant on traditional, static map products however, the ability of such products to display the complexity and temporal aspects is limited and ultimately undervalues both the knowledge incorporated in the models and the capacity of stakeholders to disseminate the complexities through other means. Geovisualization provides tools and methods for disseminating large volumes of spatial (and associated non-spatial) data. Virtual Environments (VE) have been utilised for various aspects of landscape planning for more than a decade. While such systems are capable of visualizing large volumes of data at ever-increasing levels of realism, they restrict the users ability to accurately perceive the (virtual) space. Augmented Reality (AR) is a visualization technique which allows users freedom to explore a physical space and have that space augmented with additional, spatially referenced information. A review of existing mobile AR systems forms the basis of this research. A theoretical mobile outdoor AR system using Common-Of-The-Shelf (COTS) hardware and open-source software is developed. The specific requirements for visualizing land use scenarios in a mobile AR system were derived using a usability engineering approach known as Scenario-Based Design (SBD). This determined the elements required in the user interfaces resulting in the development of a low-fidelity, computer-based prototype. The prototype user interfaces were evaluated using participants from two targeted stakeholder groups undertaking hypothetical use scenarios. Feedback from participants was collected using the cognitive walk-through technique and supplemented by evaluator observations of participants physical actions. Results from this research suggest that the prototype user interfaces did provide the necessary functionality for interacting with land use scenarios. While there were some concerns about the potential implementation of

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Recent progress in the overlay and registration of digital information on the users workspace in a spatially meaningful way has allowed mixed reality (MR) to become a more effective operational medium. In the area of medical surgery, surgeons are conveyed with information such as the incisions location, regions to be avoided, diseased tissues, etc, while staying in and keeping their original working environment. The main objective of this Thesis is identifying theoretical and practical basis for how mixed reality interfaces might provide support and augmentation maximizing the continuity of interaction. We start proposing a set of design principles organized in a design space which allows to identify continuity interaction properties at an early stage of the development system. Once the abstract design possibilities have been identified and a concrete design decision has been taken, an implementational strategy can be developed. Two approaches were investigated: markerless and marker-based. The last one is used to provide surgeons with guidance on an osteotomy task in the maxillo-facial surgery. The evaluation process applies usability tests with users to validate the augmented guidance in different scenarios and to study the influence of different design variables in the final user interaction. As a result we have found a model to describe the contribution factors of each variable for the continuity of the user interaction. We suggest that this methodology can be applied mainly to those applications in which smooth connections and interactions, with virtual and real environments, are critical for the system; i.e. surgery, drivers applications or pilot simulations.

Augmented Reality (AR) is an emerging technology that utilizes computer vision methods to overlay virtual objects onto the real world scene so as to make them appear to co-exist with the real objects. Its main objective is to enhance the user’s interaction with the real world by providing the right information needed to perform a certain task. Applications of this technology in manufacturing include maintenance, assembly and telerobotics. In this paper, we explore the potential of teaching a robot to perform an arc welding task in an AR environment. We present the motivation, features of a system using the popular ARToolkit package, and a discussion on the issues and implications of our research. / Singapore-MIT Alliance (SMA)