3,194 research outputs found

    HOLOGRAPHICS: Combining Holograms with Interactive Computer Graphics

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    Among all imaging techniques that have been invented throughout the last decades, computer graphics is one of the most successful tools today. Many areas in science, entertainment, education, and engineering would be unimaginable without the aid of 2D or 3D computer graphics. The reason for this success story might be its interactivity, which is an important property that is still not provided efficiently by competing technologies – such as holography. While optical holography and digital holography are limited to presenting a non-interactive content, electroholography or computer generated holograms (CGH) facilitate the computer-based generation and display of holograms at interactive rates [2,3,29,30]. Holographic fringes can be computed by either rendering multiple perspective images, then combining them into a stereogram [4], or simulating the optical interference and calculating the interference pattern [5]. Once computed, such a system dynamically visualizes the fringes with a holographic display. Since creating an electrohologram requires processing, transmitting, and storing a massive amount of data, today’s computer technology still sets the limits for electroholography. To overcome some of these performance issues, advanced reduction and compression methods have been developed that create truly interactive electroholograms. Unfortunately, most of these holograms are relatively small, low resolution, and cover only a small color spectrum. However, recent advances in consumer graphics hardware may reveal potential acceleration possibilities that can overcome these limitations [6]. In parallel to the development of computer graphics and despite their non-interactivity, optical and digital holography have created new fields, including interferometry, copy protection, data storage, holographic optical elements, and display holograms. Especially display holography has conquered several application domains. Museum exhibits often use optical holograms because they can present 3D objects with almost no loss in visual quality. In contrast to most stereoscopic or autostereoscopic graphics displays, holographic images can provide all depth cues—perspective, binocular disparity, motion parallax, convergence, and accommodation—and theoretically can be viewed simultaneously from an unlimited number of positions. Displaying artifacts virtually removes the need to build physical replicas of the original objects. In addition, optical holograms can be used to make engineering, medical, dental, archaeological, and other recordings—for teaching, training, experimentation and documentation. Archaeologists, for example, use optical holograms to archive and investigate ancient artifacts [7,8]. Scientists can use hologram copies to perform their research without having access to the original artifacts or settling for inaccurate replicas. Optical holograms can store a massive amount of information on a thin holographic emulsion. This technology can record and reconstruct a 3D scene with almost no loss in quality. Natural color holographic silver halide emulsion with grain sizes of 8nm is today’s state-of-the-art [14]. Today, computer graphics and raster displays offer a megapixel resolution and the interactive rendering of megabytes of data. Optical holograms, however, provide a terapixel resolution and are able to present an information content in the range of terabytes in real-time. Both are dimensions that will not be reached by computer graphics and conventional displays within the next years – even if Moore’s law proves to hold in future. Obviously, one has to make a decision between interactivity and quality when choosing a display technology for a particular application. While some applications require high visual realism and real-time presentation (that cannot be provided by computer graphics), others depend on user interaction (which is not possible with optical and digital holograms). Consequently, holography and computer graphics are being used as tools to solve individual research, engineering, and presentation problems within several domains. Up until today, however, these tools have been applied separately. The intention of the project which is summarized in this chapter is to combine both technologies to create a powerful tool for science, industry and education. This has been referred to as HoloGraphics. Several possibilities have been investigated that allow merging computer generated graphics and holograms [1]. The goal is to combine the advantages of conventional holograms (i.e. extremely high visual quality and realism, support for all depth queues and for multiple observers at no computational cost, space efficiency, etc.) with the advantages of today’s computer graphics capabilities (i.e. interactivity, real-time rendering, simulation and animation, stereoscopic and autostereoscopic presentation, etc.). The results of these investigations are presented in this chapter

    Animated Urban Surfaces: Spatial Augmented Reality in public discourse

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    Today´s projection art on public surfaces developed from the mutual approximation of painting, architecture, and lighting during centuries. The terms “Spatial Augmented Reality” (SAR) and “projection mapping” describe mostly temporary large screen projections on urban surfaces. The façade architecture becomes the screen for the content, mostly projected 2D and 3D animations. In essence, many of these artworks generate illusionistic clips deriving from the existing façade structure, allowing reality and fiction to merge audio visually. Artists, architects, curators, and institutions are increasingly aware of their responsibility related to this form of the mediatization of architecture, as shown, for example, by the Brazilian artist group Visualfarm. Their members approach their work as a counterpoint to the commercialization of public space in its appropriation by industry, propaganda, and advertising. But on the other hand, they also make a living from commercial assignments. Artists and architects often see themselves as pioneers and experimental researchers for possible developments in the coming digitized cities. By presenting various examples by selected artists like Corrie Francis Parks, Pablo Valbuena and Robert Seidel, the role of animation in connection with an alternative approach to the concepts of augmented realities within this process of social and urban evolution will be discussed. These artists try to integrate digital content into the cityscape in a harmonious sense

    Using high resolution displays for high resolution cardiac data

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    The ability to perform fast, accurate, high resolution visualization is fundamental to improving our understanding of anatomical data. As the volumes of data increase from improvements in scanning technology, the methods applied to rendering and visualization must evolve. In this paper we address the interactive display of data from high resolution MRI scanning of a rabbit heart and subsequent histological imaging. We describe a visualization environment involving a tiled LCD panel display wall and associated software which provide an interactive and intuitive user interface. The oView software is an OpenGL application which is written for the VRJuggler environment. This environment abstracts displays and devices away from the application itself, aiding portability between different systems, from desktop PCs to multi-tiled display walls. Portability between display walls has been demonstrated through its use on walls at both Leeds and Oxford Universities. We discuss important factors to be considered for interactive 2D display of large 3D datasets, including the use of intuitive input devices and level of detail aspects

    Real-time Body Tracking and Projection Mapping in the Interactive Arts

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    Projection mapping, a subtopic of augmented reality, displays computer-generated light visualizations from projectors onto the real environment. A challenge for projection mapping in performing interactive arts is dynamic body movements. Accuracy and speed are key components for an immersive application of body projection mapping and dependent on scanning and processing time. This thesis presents a novel technique to achieve real-time body projection mapping utilizing a state of the art body tracking device, Microsoft’s Azure Kinect DK, by using an array of trackers for error minimization and movement prediction. The device\u27s Sensor and Bodytracking SDKs allow multiple device synchronization. We combine our tracking results from this feature with motion prediction to provide an accurate approximation for body joint tracking. Using the new joint approximations and the depth information from the Kinect, we create a silhouette and map textures and animations to it before projecting it back onto the user. Our implementation of gesture detection provides interaction between the user and the projected images. Our results decreased the lag time created from the devices, code, and projector to create a realistic real-time body projection mapping. Our end goal was to display it in an art show. This thesis was presented at Burning Man 2019 and Delfines de San Carlos 2020 as interactive art installations

    Computer vision for interactive skewed video projection

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    CUshop: A Simulated Shopping Environment Fostering Consumer-Centric Packaging Design & Testing

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    Consumer product packaging provides product damage protection, extends product shelf life, and communicates product usage instructions to the consumer. Its collective contribution to the waste stream is notorious, but its role in product salability is much less understood. Consumers now make the majority of product purchase decisions while present at the shelf, and since they do it very quickly (within 5-8 seconds), and do not appear to adhere to strong brand loyalty as was once more common, packaging (and more specifically, its aesthetics and contrast with its competitors) plays a dominant role in the decision-making process. It is difficult, however, to measure and predict the effectiveness of package design via empirical consumer response testing, and even more challenging to seamlessly integrate consumer response measures into the package design process. The key to meaningful measurement of consumer behavior in the package design process is immersion of the consumer in a convincing environment that elicits natural shopping behavior. While an actual retail store offers the most realistic environment, controlling experimental conditions in this setting is problematic. An artificial simulation of such an environment is desirable for reasons of efficiency, cost, and flexibility. CUshop, a unique laboratory mixing physical store elements with those akin to virtual reality simulation, is introduced. The laboratory has been created with the goal of priming participants into a shopping context, or shopping frame of mind, prompting realistic consumer behavior that can be measured and studied via objective forms of measurement (e.g., eye tracking)
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