511 research outputs found

    Vision-Based Three Dimensional Hand Interaction In Markerless Augmented Reality Environment

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    Kemunculan realiti tambahan membolehkan objek maya untuk wujud bersama dengan dunia sebenar dan ini memberi kaedah baru untuk berinteraksi dengan objek maya. Sistem realiti tambahan memerlukan penunjuk tertentu, seperti penanda untuk menentukan bagaimana objek maya wujud dalam dunia sebenar. Penunjuk tertentu mesti diperolehi untuk menggunakan sistem realiti tambahan, tetapi susah untuk seseorang mempunyai penunjuk tersebut pada bila-bila masa. Tangan manusia, yang merupakan sebahagian dari badan manusia dapat menyelesaikan masalah ini. Selain itu, tangan boleh digunakan untuk berinteraksi dengan objek maya dalam dunia realiti tambahan. Tesis ini membentangkan sebuah sistem realiti tambahan yang menggunakan tangan terbuka untuk pendaftaran objek maya dalam persekitaran sebenar dan membolehkan pengguna untuk menggunakan tangan yang satu lagi untuk berinteraksi dengan objek maya yang ditambahkan dalam tiga-matra. Untuk menggunakan tangan untuk pendaftaran dan interaksi dalam realiti tambahan, postur dan isyarat tangan pengguna perlu dikesan. The advent of augmented reality (AR) enables virtual objects to be superimposed on the real world and provides a new way to interact with the virtual objects. AR system requires an indicator to determine for how the virtual objects aligned in the real world. The indicator must first be obtained to access to a particular AR system. It may be inconvenient to have the indicator in reach at all time. Human hand, which is part of the human body may be a solution for this. Besides, hand is also a promising tool for interaction with virtual objects in AR environment. This thesis presents a markerless Augmented Reality system which utilizes outstretched hand for registration of virtual objects in the real environment and enables the users to have three dimensional (3D) interaction with the augmented virtual objects. To employ the hand for registration and interaction in AR, hand postures and gestures that the user perform has to be recognized

    Augmented Reality as a Potential Tool for Filmmaking

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    Augmented Reality (AR) has been used for a wide variety of industries. The purpose of this study was to determine the suitability of this technology for use in filmmaking. One of the problems on a film set is the time taken to block a scene. Blocking involves the placement of subjects and props within a scene. Different ideas have been used for blocking including previzualisation and Virtual Reality (VR). This study proposesed the use of AR as a tool to solve this problem. Marker-based and Markerless AR were assessed in turn to determine their suitability for addressing the problem. The use of AR markers and QR codes were examined in comparison with the use of Simultaneous Localization and Mapping (SLAM) imple mentations. The marker-based AR requires a physical object to scan and markerless is done via the mapping of GPS coordinates. Experiments were conducted on the accu racy and code required for each type of AR. These involved calculating the distances from the marker and the code required to create the virtual content. Surveys and expert interviews were conducted with filmakers and people working in the AR industry to determine the usability and feasibility of the proposed application. This provided a qualitative approach to the technology as the acceptance of any new system is of equal importance to how it functions

    Optical and hyperspectral image analysis for image-guided surgery

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    Optical and hyperspectral image analysis for image-guided surgery

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    Keyframe Tagging: Unambiguous Content Delivery for Augmented Reality Environments

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    Context: When considering the use of Augmented Reality to provide navigation cues in a completely unknown environment, the content must be delivered into the environment with a repeatable level of accuracy such that the navigation cues can be understood and interpreted correctly by the user. Aims: This thesis aims to investigate whether a still image based reconstruction of an Augmented Reality environment can be used to develop a content delivery system that providers a repeatable level of accuracy for content placement. It will also investigate whether manipulation of the properties of a Spatial Marker object is sufficient to reduce object selection ambiguity in an Augmented Reality environment. Methods: A series of experiments were conducted to test the separate aspects of these aims. Participants were required to use the developed Keyframe Tagging tool to introduce virtual navigation markers into an Augmented Reality environment, and also to identify objects within an Augmented Reality environment that was signposted using different Virtual Spatial Markers. This tested the accuracy and repeatability of content placement of the approach, while also testing participants’ ability to reliably interpret virtual signposts within an Augmented Reality environment. Finally the Keyframe Tagging tool was tested by an expert user against a pre-existing solution to evaluate the time savings offered by this approach against the overall accuracy of content placement. Results: The average accuracy score for content placement across 20 participants was 64%, categorised as “Good” when compared with an expert benchmark result, while no tags were considered “incorrect” and only 8 from 200 tags were considered to have “Poor” accuracy, supporting the Keyframe Tagging approach. In terms of object identification from virtual cues, some of the predicted cognitive links between virtual marker property and target object did not surface, though participants reliably identified the correct objects across several trials. Conclusions: This thesis has demonstrated that accurate content delivery can be achieved through the use of a still image based reconstruction of an Augmented Reality environment. By using the Keyframe Tagging approach, content can be placed quickly and with a sufficient level of accuracy to demonstrate its utility in the scenarios outlined within this thesis. There are some observable limitations to the approach, which are discussed with the proposals for further work in this area

    ISAR: Ein Autorensystem für Interaktive Tische

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    Developing augmented reality systems involves several challenges, that prevent end users and experts from non-technical domains, such as education, to experiment with this technology. In this research we introduce ISAR, an authoring system for augmented reality tabletops targeting users from non-technical domains. ISAR allows non-technical users to create their own interactive tabletop applications and experiment with the use of this technology in domains such as educations, industrial training, and medical rehabilitation.Die Entwicklung von Augmented-Reality-Systemen ist mit mehreren Herausforderungen verbunden, die Endbenutzer und Experten aus nicht-technischen Bereichen, wie z.B. dem Bildungswesen, daran hindern, mit dieser Technologie zu experimentieren. In dieser Forschung stellen wir ISAR vor, ein Autorensystem für Augmented-Reality-Tabletops, das sich an Benutzer aus nicht-technischen Bereichen richtet. ISAR ermöglicht es nicht-technischen Anwendern, ihre eigenen interaktiven Tabletop-Anwendungen zu erstellen und mit dem Einsatz dieser Technologie in Bereichen wie Bildung, industrieller Ausbildung und medizinischer Rehabilitation zu experimentieren

    Robot guidance using machine vision techniques in industrial environments: A comparative review

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    In the factory of the future, most of the operations will be done by autonomous robots that need visual feedback to move around the working space avoiding obstacles, to work collaboratively with humans, to identify and locate the working parts, to complete the information provided by other sensors to improve their positioning accuracy, etc. Different vision techniques, such as photogrammetry, stereo vision, structured light, time of flight and laser triangulation, among others, are widely used for inspection and quality control processes in the industry and now for robot guidance. Choosing which type of vision system to use is highly dependent on the parts that need to be located or measured. Thus, in this paper a comparative review of different machine vision techniques for robot guidance is presented. This work analyzes accuracy, range and weight of the sensors, safety, processing time and environmental influences. Researchers and developers can take it as a background information for their future works

    Development of an augmented reality guided computer assisted orthopaedic surgery system

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    Previously held under moratorium from 1st December 2016 until 1st December 2021.This body of work documents the developed of a proof of concept augmented reality guided computer assisted orthopaedic surgery system – ARgCAOS. After initial investigation a visible-spectrum single camera tool-mounted tracking system based upon fiducial planar markers was implemented. The use of visible-spectrum cameras, as opposed to the infra-red cameras typically used by surgical tracking systems, allowed the captured image to be streamed to a display in an intelligible fashion. The tracking information defined the location of physical objects relative to the camera. Therefore, this information allowed virtual models to be overlaid onto the camera image. This produced a convincing augmented experience, whereby the virtual objects appeared to be within the physical world, moving with both the camera and markers as expected of physical objects. Analysis of the first generation system identified both accuracy and graphical inadequacies, prompting the development of a second generation system. This too was based upon a tool-mounted fiducial marker system, and improved performance to near-millimetre probing accuracy. A resection system was incorporated into the system, and utilising the tracking information controlled resection was performed, producing sub-millimetre accuracies. Several complications resulted from the tool-mounted approach. Therefore, a third generation system was developed. This final generation deployed a stereoscopic visible-spectrum camera system affixed to a head-mounted display worn by the user. The system allowed the augmentation of the natural view of the user, providing convincing and immersive three dimensional augmented guidance, with probing and resection accuracies of 0.55±0.04 and 0.34±0.04 mm, respectively.This body of work documents the developed of a proof of concept augmented reality guided computer assisted orthopaedic surgery system – ARgCAOS. After initial investigation a visible-spectrum single camera tool-mounted tracking system based upon fiducial planar markers was implemented. The use of visible-spectrum cameras, as opposed to the infra-red cameras typically used by surgical tracking systems, allowed the captured image to be streamed to a display in an intelligible fashion. The tracking information defined the location of physical objects relative to the camera. Therefore, this information allowed virtual models to be overlaid onto the camera image. This produced a convincing augmented experience, whereby the virtual objects appeared to be within the physical world, moving with both the camera and markers as expected of physical objects. Analysis of the first generation system identified both accuracy and graphical inadequacies, prompting the development of a second generation system. This too was based upon a tool-mounted fiducial marker system, and improved performance to near-millimetre probing accuracy. A resection system was incorporated into the system, and utilising the tracking information controlled resection was performed, producing sub-millimetre accuracies. Several complications resulted from the tool-mounted approach. Therefore, a third generation system was developed. This final generation deployed a stereoscopic visible-spectrum camera system affixed to a head-mounted display worn by the user. The system allowed the augmentation of the natural view of the user, providing convincing and immersive three dimensional augmented guidance, with probing and resection accuracies of 0.55±0.04 and 0.34±0.04 mm, respectively

    Recent Developments and Future Challenges in Medical Mixed Reality

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    As AR technology matures, we have seen many applicationsemerge in entertainment, education and training. However, the useof AR is not yet common in medical practice, despite the great po-tential of this technology to help not only learning and training inmedicine, but also in assisting diagnosis and surgical guidance. Inthis paper, we present recent trends in the use of AR across all med-ical specialties and identify challenges that must be overcome tonarrow the gap between academic research and practical use of ARin medicine. A database of 1403 relevant research papers publishedover the last two decades has been reviewed by using a novel re-search trend analysis method based on text mining algorithm. Wesemantically identified 10 topics including varies of technologiesand applications based on the non-biased and in-personal cluster-ing results from the Latent Dirichlet Allocatio (LDA) model andanalysed the trend of each topic from 1995 to 2015. The statisticresults reveal a taxonomy that can best describes the developmentof the medical AR research during the two decades. And the trendanalysis provide a higher level of view of how the taxonomy haschanged and where the focus will goes. Finally, based on the valu-able results, we provide a insightful discussion to the current limi-tations, challenges and future directions in the field. Our objectiveis to aid researchers to focus on the application areas in medicalAR that are most needed, as well as providing medical practitioners with latest technology advancements
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