Mobile vision based augmented reality navigation system

Augmented reality applications become more and more popular due to increasing computation speed of the mobile handsets and need of easy and intuitive navigation. Existing systems are implemented on the basis of GPS and compass where relative position and orientation of the handset is considered. Such hardware requirements decrease amount of compatible devices and limits system usage to outdoors where GPS signal is available. The paper presents a vision-based augmented reality navigation system implemented on the Android mobile phone. Image data of interest object and handset position are acquired by the users, however GPS position is not required for the system operation

Mobile Augmented Reality: User Interfaces, Frameworks, and Intelligence

Mobile Augmented Reality (MAR) integrates computer-generated virtual objects with physical environments for mobile devices. MAR systems enable users to interact with MAR devices, such as smartphones and head-worn wearables, and perform seamless transitions from the physical world to a mixed world with digital entities. These MAR systems support user experiences using MAR devices to provide universal access to digital content. Over the past 20 years, several MAR systems have been developed, however, the studies and design of MAR frameworks have not yet been systematically reviewed from the perspective of user-centric design. This article presents the first effort of surveying existing MAR frameworks (count: 37) and further discuss the latest studies on MAR through a top-down approach: (1) MAR applications; (2) MAR visualisation techniques adaptive to user mobility and contexts; (3) systematic evaluation of MAR frameworks, including supported platforms and corresponding features such as tracking, feature extraction, and sensing capabilities; and (4) underlying machine learning approaches supporting intelligent operations within MAR systems. Finally, we summarise the development of emerging research fields and the current state-of-the-art, and discuss the important open challenges and possible theoretical and technical directions. This survey aims to benefit both researchers and MAR system developers alike.Peer reviewe

Registro espacial 2D–3D para a inspeção remota de subestações de energia

Remote inspection and supervisory control are critical features for smart factories, civilian surveillance, power systems, among other domains. For reducing the time to make decisions, operators must have both a high situation awareness, implying a considerable amount of data to be presented, and minimal sensory load. Recent research suggests the adoption of computer vision techniques for automatic inspection, as well as virtual reality (VR) as an alternative to traditional SCADA interfaces. Nevertheless, although VR may provide a good representation of a substation’s state, it lacks some real-time information, available from online field cameras and microphones. Since these two sources of information (VR and field information) are not integrated into one single solution, we miss the opportunity of using VR as a SCADA-aware remote inspection tool, during operation and disaster-response routines. This work discusses a method to augment virtual environments of power substations with field images, enabling operators to promptly see a virtual representation of the inspected area's surroundings. The resulting environment is integrated with an image-based state inference machine, continuously checking the inferred states against the ones reported by the SCADA database. Whenever a discrepancy is found, an alarm is triggered and the virtual camera can be immediately teleported to the affected region, speeding up system reestablishment. The solution is based on a client-server architecture and allows multiple cameras deployed in multiple substations. Our results concern the quality of the 2D–3D registration and the rendering framerate for a simple scenario. The collected quantitative metrics suggest good camera pose estimations and registrations, as well as an arguably optimal rendering framerate for substations' equipment inspection.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCEMIG - Companhia Energética de Minas GeraisCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas GeraisTese (Doutorado)A inspeção remota e o controle supervisório são requisitos críticos para fábricas modernas, vigilância de civis, sistemas de energia e outras áreas. Para reduzir o tempo da tomada de decisão, os operadores precisam de uma elevada consciência da situação em campo, o que implica em uma grande quantidade de dados a serem apresentados, mas com menor carga sensorial possível. Estudos recentes sugerem a adoção de técnicas de visão computacional para inspeção automática, e a Realidade Virtual (VR) como uma alternativa às interfaces tradicionais do SCADA. Entretanto, apesar de fornecer uma boa representação do estado da subestação, os ambientes virtuais carecem de algumas informações de campo, provenientes de câmeras e microfones. Como essas duas fontes de dados (VR e dispositivos de captura) não são integrados em uma única solução, perde-se a oportunidade de usar VR como uma ferramenta de inspeção remota conectada ao SCADA, durante a operação e rotinas de respostas a desastres. Este trabalho trata de um método para aumentar ambientes virtuais de subestações com imagens de campo, permitindo aos operadores a rápida visualização de uma representação virtual do entorno da área monitorada. O ambiente resultante é integrado com uma máquina de inferência estados por imagens, comparando continuamente os estados inferidos com aqueles reportados pela base SCADA. Na ocasião de uma discrepância, um alarme é gerado e possibilita que a câmera virtual seja imediatamente teletransportada para a região afetada, acelerando o processo de retomada do sistema. A solução se baseia em uma arquitetura cliente-servidor e permite múltiplas câmeras presentes em múltiplas subestações. Os resultados dizem respeito à qualidade do registro 2D–3D e à taxa de renderização para um cenário simples. As métricas quantitativas coletadas sugerem bons níveis de registro e estimativa de pose de câmera, além de uma taxa ótima de renderização para fins de inspeção de equipamentos em subestações

THE UNIVERSAL MEDIA BOOK

We explore the integration of projected imagery with a physical book that acts as a tangible interface to multimedia data. Using a camera and projector pair, a tracking framework is presented wherein the 3D position of planar pages are monitored as they are turned back and forth by a user, and data is correctly warped and projected onto each page at interactive rates to provide the user with an intuitive mixed-reality experience. The book pages are blank, so traditional camera-based approaches to tracking physical features on the display surface do not apply. Instead, in each frame, feature points are independently extracted from the camera and projector images, and matched to recover the geometry of the pages in motion. The book can be loaded with multimedia content, including images and videos. In addition, volumetric datasets can be explored by removing a page from the book and using it as a tool to navigate through a virtual 3D volume

Selected Topics in Bayesian Image/Video Processing

In this dissertation, three problems in image deblurring, inpainting and virtual content insertion are solved in a Bayesian framework.;Camera shake, motion or defocus during exposure leads to image blur. Single image deblurring has achieved remarkable results by solving a MAP problem, but there is no perfect solution due to inaccurate image prior and estimator. In the first part, a new non-blind deconvolution algorithm is proposed. The image prior is represented by a Gaussian Scale Mixture(GSM) model, which is estimated from non-blurry images as training data. Our experimental results on a total twelve natural images have shown that more details are restored than previous deblurring algorithms.;In augmented reality, it is a challenging problem to insert virtual content in video streams by blending it with spatial and temporal information. A generic virtual content insertion (VCI) system is introduced in the second part. To the best of my knowledge, it is the first successful system to insert content on the building facades from street view video streams. Without knowing camera positions, the geometry model of a building facade is established by using a detection and tracking combined strategy. Moreover, motion stabilization, dynamic registration and color harmonization contribute to the excellent augmented performance in this automatic VCI system.;Coding efficiency is an important objective in video coding. In recent years, video coding standards have been developing by adding new tools. However, it costs numerous modifications in the complex coding systems. Therefore, it is desirable to consider alternative standard-compliant approaches without modifying the codec structures. In the third part, an exemplar-based data pruning video compression scheme for intra frame is introduced. Data pruning is used as a pre-processing tool to remove part of video data before they are encoded. At the decoder, missing data is reconstructed by a sparse linear combination of similar patches. The novelty is to create a patch library to exploit similarity of patches. The scheme achieves an average 4% bit rate reduction on some high definition videos