76 research outputs found

    Exploring the optical perception of image within glass

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    Within the contemporary world, 3D film and television imagery is at the cutting edge of visual technology, but for centuries we have been captivated by the creation of visual illusions/allusions that play with our perception of the world, from the auto-stereoscopic barrier methods pioneered in the late 17th century by the French painter G. A. Bois-Clair to the ‘Op’ art movement of the 1960s and, more recently, Patrick Hughes’ ‘reverse perspective’ paintings. By building on these new and old technologies I have extended my own practice, which engages with the 2D image as a 3D allusion/illusion in glass, by examining how this type of image can be created and perceived within glass. I have explored theories of optical perception in connection with the binocular recognition of depth and space, as well as kinetic clues to distance through motion parallax monitoring and assumptions about default linear perspective, light and inference within our personal schemata. - ‘Optical illusion’ is used to mean an instance of a wrong or misinterpreted perception of a sensory experience; the distortion of senses revealing how the brain organises and interprets visual information; an individual’s ability to perceive depth, 3D form and motion. - ‘Allusion’ is used to imply a symbolic or covert reference. My practical research focuses on the perceived creation of the 3D image within glass and explores the notion of glass as a facilitator in working with and challenging the themes of 3D image perception. I have particularly addressed artistic spatial illusionary methods, reverse perspective techniques, auto-stereoscopic image-based systems, parallax stereograms and lenticular print and lens technology. Through building on my previous practice of working with multiple-layered images within cast glass, combined with more complex and scientific optical methods, I have explored the perception of the image by working with new and old 3D technologies in order to produce a body of work which examines this perception within glass. During my research I have developed an original casting process, a vacuum-casting lost wax process for glass, in addition to producing an accurate industry standard lenticular glass lens. This research intends to provide a theoretical basis for new glass working techniques, both within the glass artist’s studio and in the commercial world of print, towards applications within architectural design, installation art and image-based artwork in general. This thesis is therefore a summation of the research that I have undertaken over the past six years and an attempt to give substance to the ideas and references that have preoccupied my own investigations over that period. I have structured the thesis into three themes: perspective; perception; and process but those three elements were never separate from each other and not only do they depend on each other, their purpose is, in some way, to combine in the creation of my finished pieces

    Hybrid stereoscopic photography - Analogue stereo photography meets the digital age with the StereoCompass app

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    Stereoscopic photography has a long history which started just a few years after the first known photo was taken: 1849 Sir David Brewster introduced the first binocular camera. Whereas mobile photography is omnipresent because of the wide distribution of smart phones, stereoscopic photography is only used by a very small set of enthusiasts or professional (stereo) photographers. One important aspect of professional stereoscopic photography is that the required technology is usually quite expensive. Here, we present an alternative approach, uniting easily affordable vintage analogue SLR cameras with smart phone technology to measure and predict the stereo base/camera separation as well as the focal distance to zero parallax. For this purpose, the StereoCompass app was developed which is utilizing a number of smart phone sensors, combined with a Google Maps-based distance measure- ment. Three application cases including red/cyan anaglyph stereo photographs are shown. More information and the app can be found at: http://stereocompass.i2d.u

    Using Serious Games to Create Awareness on Visual Impairments

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    Visual impairments define a wide spectrum of disabilities that vary in severity, from the need to wear glasses, to permanent loss of vision or blindness. This paper discusses the process undertaken in creating two simulators, one which emulates partially-sighted visual impairment and another focused on full -blindness. In order to create the simulators, extensive research was conducted surrounding the effects of partially-sightedness and blindness, highlighting existing software and games that promote awareness for visual impairments. This paper underlines the necessity of raising awareness for visual impairments and the effectiveness of applying serious games for this very goal. After developing the simulators, experiments were conducted to evaluate the effectiveness of it. Findings from the experiments were analysed and documented

    Simulação de acomodação e aberrações de baixa ordem do olho humano usando árvores de coleta de luz

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    In this work, we present two practical solutions for simulating accommodation and loworder aberrations of optical systems, such as the human eye. Taking into account pupil size (aperture) and accommodation (focal distance), our approaches model the corresponding point spread function and produce realistic depth-dependent simulations of low-order visual aberrations (e.g., myopia, hyperopia, and astigmatism). In the first solution, we use wave optics to extend the notion of Depth Point Spread Function, which originally relies on ray tracing, to perform the generation of point spread functions using Fourier optics. In the other technique, we use geometric optics to build a light-gathering tree data structure, presenting a solution to the problem of artifacts caused by absence of occluded pixels in the input discretized depth images. As such, the resulting images show seamless transitions among elements at different scene depths. We demonstrate the effectiveness of our approaches through a series of quantitative and qualitative experiments on images with depth obtained from real environments. Our results achieved SSIM values above 0.94 and PSNR above 32.0 in all objective evaluations, indicating strong agreement with the ground-truth.Neste trabalho, apresentamos duas técnicas de simulação de acomodação e aberrações de baixa ordem de sistemas ópticos, tais como o olho humano. Nossos algoritmos lançam mão de determinadas informações, tais como o tamanho da pupila e a acomodação (distância focal), com o objetivo de modelar a função de espalhamento pontual (point spread function) do sistema, resultando na produção de simulações realistas de aberrações de baixa ordem (p.e., miopia, hipermetropia e astigmatismo). Nossas simulações levam também em consideração as distâncias dos objetos que compõem a cena a fim de aplicar o borramento apropriado. A primeira técnica estende o conceito de Função de Espalhamento Pontual com Profundidade (Depth Point Spread Function), originalmente construída mediante o traçado de raios (ray tracing), que passa então a ser gerada por meio de métodos da óptica de Fourier. A segunda técnica, por sua vez, utiliza-se da óptica geométrica para construir uma estrutura de dados em forma de árvore. Esta árvore é então utilizada para simular a propagação da luz no ambiente, gerando os efeitos de borramento esperados, e de quebra soluciona o problema de artefatos visuais causados pela ausência de informação na imagem original (provocada pela oclusão parcial entre elementos da cena). Nós demonstramos a efetividade de nossos algoritmos por meio de uma série de experimentos quantitativos e qualitativos em imagens com profundidade obtidas de ambientes reais. Nossos resultados alcançaram valores de SSIM superiores a 0,94 e valores de PSNR superiores a 32,0 em todas as avaliações objetivas, o que indica uma expressiva concordância com as imagens de referência

    Impressão lenticular: autostereoscopic prints for advertising

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    O objetivo deste projeto é demonstrar o resultado da interação da modelagem 3D com a tecnologia de impressão lenticular, e encontrar um caminho para sua aplicação prática no universo da publicidade. O projeto explora os exemplos históricos de arte imersiva e sua utilização diversa na prática, aborda os fatores que influenciam a percepção humana de profundidade e também analisa vários métodos usados para produzir impressões estereoscópicas, a própria tecnologia lenticular e técnicas de publicidade. Através do método de design surge uma solução criativa e o trabalho final é realizado na forma física de um poster de impressão lenticular, que é uma proposta da sua utilização como estratégia de comunicação.The objective of this project is to demonstrate the result of mixing 3D modeling with lenticular printing technology, and find a way for its practical application in the world of advertising. The project explores historical examples of immersive art and its diverse use in practice. It addresses the factors that influence human depth perception and also explores various methods used to produce stereoscopic prints, lenticular technology itself, and advertising techniques. Through the design method, a creative solution emerges and the final work is carried out in the physical form of a lenticular poster, which is a proposition of its use as a communication strategy

    Making modality: transmodal composing in a digital media studio.

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    The multiple media that exist for communication have historically been theorized as possessing different available means for persuasion and meaning-making. The exigence of these means has been the object of theoretical debate that ranges from cultural studies, language studies, semiology, and philosophies of the mind. This dissertation contributes to such debates by sharing the results of an ethnographically informed study of multimedia composing in a digital media studio. Drawing from Cultural Historical Activity Theory and theories of enactive perception, I analyze the organizational and infrastructural design of a media studio as well as the activity of composer/designers working in said studio. Throughout this analysis I find that implicit in the organization and infrastructure of the media studio is an ethos of conceptualizing communication technology as a legitimizing force. Such an ethos is troubled by my analysis of composer/designers working in the studio, whose activities do not seek outside legitimization but instead contribute to the media milieu. Following these analyses, I conclude that media’s means for persuasion and meaning-making emerge from local practices of communication and design. Finally, I provide a framework for studying the emergence of such means

    Utilization of photogrammetry during establishment of virtual rock collection at Aalto University

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    In recent years, we can observe increasing popularity of the term industry 4.0 which is defined as a new level of organization and control over the entire value chain of the life cycle of products. Experts distinguished nine different technologies, which are essential for the development of industry 4.0. One of them is virtual reality, which is used during processes of data visualisation and digitization. These processes can also include geological collections. Due to limited access to different geological spots, the popularity of destructive techniques during rock testing and high complexity of the process of learning geosciences, geologists are looking for new methods of digitization of different samples of rocks and minerals. The aim of this master thesis was to create a virtual collection of selected rocks and minerals using photogrammetry and virtual reality (VR) technology and develop new tool and interactive learning platform for study mineralogy and petrography. To accomplish these aims and create 3D models of specimens, the author built professional photo studio and used photogrammetric techniques to digitize the samples. The main output of this research is a virtual 3D collection of rocks and minerals that consisting of 107 samples, and which is available via two different channels: Sketchfab portal online model repository and VR environment built in Unity game engine. The virtual collection will be utilised to teach students how to identify rocks and minerals at Aalto University

    Real-Time deep image rendering and order independent transparency

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    In computer graphics some operations can be performed in either object space or image space. Image space computation can be advantageous, especially with the high parallelism of GPUs, improving speed, accuracy and ease of implementation. For many image space techniques the information contained in regular 2D images is limiting. Recent graphics hardware features, namely atomic operations and dynamic memory location writes, now make it possible to capture and store all per-pixel fragment data from the rasterizer in a single pass in what we call a deep image. A deep image provides a state where all fragments are available and gives a more complete image based geometry representation, providing new possibilities in image based rendering techniques. This thesis investigates deep images and their growing use in real-time image space applications. A focus is new techniques for improving fundamental operation performance, including construction, storage, fast fragment sorting and sampling. A core and driving application is order-independent transparency (OIT). A number of deep image sorting improvements are presented, through which an order of magnitude performance increase is achieved, significantly advancing the ability to perform transparency rendering in real time. In the broader context of image based rendering we look at deep images as a discretized 3D geometry representation and discuss sampling techniques for raycasting and antialiasing with an implicit fragment connectivity approach. Using these ideas a more computationally complex application is investigated — image based depth of field (DoF). Deep images are used to provide partial occlusion, and in particular a form of deep image mipmapping allows a fast approximate defocus blur of up to full screen size
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