107 research outputs found

    Heterogeneous information integration for mountain augmented reality mobile apps

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    Mobile Augmented Reality (AR) applications offer a new way to promote the collection of geo-referenced information, by engaging citizens in a useful experience and encouraging them to gather environment data, such as images of plant species or of mountain snow coverage. The distinctive characteristic of mobile AR applications is the overlay of information directly on top of what the user sees, based on the user’s context estimated from the device sensors. The application analyzes the sensor readings (GPS position, phone orientation and motion, and possibly also the camera frame content), to understand what the user is watching and enriches the view with contextual information. Developing mobile AR applications poses several challenges related to the acquisition, selection, transmission and display of information, which gets more demanding in mountain applications where usage without Internet connectivity is a strong requirement. This paper discusses the experience of a real world mobile AR application for mountain exploration, which can be used to crowdsource the collection of mountain images for environmental purposes, such as the analysis of snow coverage for water availability prediction and the monitoring of plant diseases

    Foveation scalable video coding with automatic fixation selection

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    Objective measurement of motion in the orbit

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    The research described in the thesis had two major aims: to find methods for objective measurement of motion in the orbit, and to determine the clinical use of these methods in patients with orbital disorders. This implied that a number of research questions had to be answered in the fields of both image science and of ophthalmology and orbitology. The results have established that measurement of the two- and three-dimensional motion of tissues in the orbit is feasible in humans. It can be imaged in 2-D and 3-D with Magnetic Resonance Imaging (MRI) sequences. It can be calculated objectively from these sequences using optical flow methods. First order techniques were found to be superior for this purpose as they are less sensitive to noise, partial volume effects and aliasing. A new first-order 3-D optical flow algorithm was developed for robust and computationally efficient three-dimensional optical flow estimation. A number of techniques were developed to visualize 2- and 3-D motion combined with the anatomy in 3-D space, using color-coding. The results of two clinical studies have established the clinical use of objective measurement of motion in the orbit in a number of orbital and motion disorders. The studies have resulted in an explanation for the persistent pain that may occur after enucleation of the globe, based on motion measurements in patients after enucleation. They have also shown that orbital tumors can be differentiated using motion studies. The results have also shown that the position of the rectus muscle pulleys is the same in patients with Graves disease and in normals. After surgical decompression of the orbit, the muscles and their pulleys are usually not displaced, except in cases where specific muscle paths and pulleys are displaced in specific patterns, resulting in specific motility disturbances. Thus, a new explanation has been found for the motility disturbances that may occur in some patients after decompression surgery for Graves orbitopathy. These last findings have led to the notion central to this thesis, namely that the orbital tissues are an organ in their own right, the organ of gaze, and do not need their bony orbit to function normally

    Noise-based Enhancement for Foveated Rendering

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    Human visual sensitivity to spatial details declines towards the periphery. Novel image synthesis techniques, so-called foveated rendering, exploit this observation and reduce the spatial resolution of synthesized images for the periphery, avoiding the synthesis of high-spatial-frequency details that are costly to generate but not perceived by a viewer. However, contemporary techniques do not make a clear distinction between the range of spatial frequencies that must be reproduced and those that can be omitted. For a given eccentricity, there is a range of frequencies that are detectable but not resolvable. While the accurate reproduction of these frequencies is not required, an observer can detect their absence if completely omitted. We use this observation to improve the performance of existing foveated rendering techniques. We demonstrate that this specific range of frequencies can be efficiently replaced with procedural noise whose parameters are carefully tuned to image content and human perception. Consequently, these fre- quencies do not have to be synthesized during rendering, allowing more aggressive foveation, and they can be replaced by noise generated in a less expensive post-processing step, leading to improved performance of the ren- dering system. Our main contribution is a perceptually-inspired technique for deriving the parameters of the noise required for the enhancement and its calibration. The method operates on rendering output and runs at rates exceeding 200 FPS at 4K resolution, making it suitable for integration with real-time foveated rendering systems for VR and AR devices. We validate our results and compare them to the existing contrast enhancement technique in user experiments

    SUPER MULTI-VIEW NEAR-EYE DISPLAY WITH LED ARRAY AND WAVEGUIDE ILLUMINATION MODULE

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    A near-eye display includes an array of light sources, a reflective spatial light modulator (SLM) synchronized with the array of light sources and configured to modulate and reflect incident light beams to generate images, display optics configured to project the images generated by the reflective SLM to a user’s eye, and a waveguide between the display optics and the reflective SLM, where the waveguide is configured to guide light beams emitted by the array of light sources and direct the light beams towards the reflective SLM to illuminate the reflective SL

    Hill top housing: Reconfiguring the suburban condition

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    Blandness and paranoia in the architecture of the domestic realm has, to a great degree, been influenced by the current mode of information--the act of viewing this information, its pacing, and its rhythm. Reality is perceived in the information realm, while the experiential, physical "world of things" is unreal. We live in a commodified environment of projections from passively received information. The project is situated in the suburban condition of Daly City, California, and it is this model of society which is economic and information based that demands consideration. The articulation of the spaces in the Daly City dwelling project attempts to project an image of suburban patterns which have been reconfigured by forces of topography, perception and the physical body, information, and the automobile. What was once responsive to a narrow range of forces has become intertwined and "flowing" with a kind of momentum in the architectural elements which make the dwelling experience

    Élelmiszervizsgálati közlemények = Journal of food investigation - 65. évf. (2019) 3. sz.

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