This thesis studies the coded aperture camera, a device consisting of a conventional camera with a modified aperture mask, that enables the recovery of both depth map and all-in-focus image from a single 2D input image. Key contributions of this work are the modeling of the statistics of natural images and the design of efficient blur identification methods in a Bayesian framework. Two cases are distinguished: 1) when the aperture can be decomposed in a small set of identical holes, and 2) when the aperture has a more general configuration. In the first case, the formulation of the problem incorporates priors about the statistical variation of the texture to avoid ambiguities in the solution. This allows to bypass the recovery of the sharp image and concentrate only on estimating depth. In the second case, the depth reconstruction is addressed via convolutions with a bank of linear filters. Key advantages over competing methods are the higher numerical stability and the ability to deal with large blur. The all-in-focus image can then be recovered by using a deconvolution step with the estimated depth map. Furthermore, for the purpose of depth estimation alone, the proposed algorithm does not require information about the mask in use. The comparison with existing algorithms in the literature shows that the proposed methods achieve state-of-the-art performance. This solution is also extended for the first time to images affected by both defocus and motion blur and, finally, to video sequences with moving and deformable objects.

Advances in printing technologies in the late 19th century led to the development of half-toning techniques enabling the economical reproduction of photographic images in print. Whilst undoubtedly successful in low cost high volume image reproduction, half-toning representations are less faithful in detail when compared to continuous tone photomechanical methods in use at that time. This thesis asks the question: can the creative application of 21st century digital fabrication technologies enable the qualities of continuous tone imaging to be regained? In the 21st-century, printmaking may be seen as the interchange of ideas, experimental practice and interdisciplinary thinking. Printmaking has always been a means of combining modern technology and methods with existing traditional and commercial imaging processes. Technological advancement in print however does not always provide a finer quality of print. Qualities often attributed to pre-digital continuous tone printing can be lost in the transition to a digital half tone print workflow. This research project examines a near obsolete 19th century print process, the continuous tone Woodburytype, developed to address the issue of permanence in photography. Through a methodological approach analyses of the Woodburytype an empirical reconstruction of the process provides a comprehensive critique of its method. The Woodburytype’s surface qualities are not found in other photomechanical printing methods capable of rendering finely detailed photographic images. Its method of image translation results in the printed tonal range being directly proportional to the deposition thickness of the printing ink, however it never successfully developed into a colour process. By examining and evaluating digital imaging technology this study identifies, current computer aided design and manufacturing techniques and extends upon known models of Woodburytype printing through the development of this deposition height quality enabling a new digital polychromatic colour printing process.

Subtopia aims to build a cognitive map of the contemporary condition of the New Towns in the United Kingdom. The written argument proposes an archaeology of the visual paradigms that inform the photographic representation of landscape and architecture. It investigates and discusses the history and the historiography of those visual paradigms through the scrutiny of content (subject) and form (aesthetics) in order to acknowledge a critical viewpoint to the photographs of Subtopia. Assuming a descriptive mood, the photographs of the visual component endorse landscape as a cultural construction. They look into urbanism and architecture as ideological epitomes, seen through the organization of public spaces. As visual fragments of a non-existent whole, the intent is to create an imaginary new town by assembling photographs from five different towns, chosen according to the different historical and political phases of the New Towns programme: Stevenage (1946), Harlow (1947), Cumbernauld (1955) Runcorn (1964) and Milton Keynes (1967). The thesis contributes to new knowledge in the history and the historiography of the New Towns in Britain. The written theory proposes a critical investigation of historical representations of architecture and the urban space, discussing the cultural environment that informed the photographs. Aiming to go beyond the sheer contextualization of the visual component, the writing examines how photographs engage with the discourses of history, architecture and urbanism. Through a dual subjective mode, as documents and as artistic representations, the photographs of the visual component Subtopia look at and trace distinctive elements of the landscape design and architecture, aiming to create an allegory of the New Towns Programme. Ultimately, the thesis proposes a new understanding in the representation of the ‘social’ landscape and the ideological expectations of the post-war urban planning in Britain.

Through practice-based research, this thesis poses the following question: To what extent can an artist use the digital camera and its processing as a prosthesis for human vision and embodiment in order to produce artworks that propose a relationship to the object world that corresponds to the exploration of a singular vision? Can the moving image operate between perception, representation and imagination? Can the moving image engage its viewers in a manner similar to painting? What forms of installation can correspond to these research questions? Triangulating a fine art practice in moving images with theoretical research into the philosophical analyses of perception, prosthesis, Flux-Image and the Matrixial Gaze, and with comparative studies of the practices of contemporary artists working with the moving image and varieties of installation, this thesis researches the relationship between the human subject, digital photographic prostheses and the external world with specific relation to time. Chapter One provides an analytical account of my work and exhibitions to explain the major questions I explore through practice. Chapter Two proposes a series of theoretical frameworks structured by the cultural and linguistic studies of prosthesis, a study of Paul Cézanne and the phenomenological concerns of being-in-the-world by Maurice Merleau-Ponty, Deleuzian notions of cinematic movement/memories/time, Christine Buci-Glucksmann’s Flux-Image and Bracha Ettinger’s the Matrixial Gaze and Metramorphosis. In Chapter Three, works and installation practices of three moving–image–based artists, Pipilotti Rist, Hilary Lloyd and Elizaeth Price, are introduced in order to explore modes of video installation. The thesis concludes with the presentation of the final exhibition See the Seeing (July 2015). Digital prosthesis is not only a tool for generating archives and documentary effects. The thesis concludes that it also provides an alternative way of perceiving and imaging the world. The thesis examines the question of artworks’ escaping from the conventional role of photo-mechanical image in representation and communication to see how moving-image artworks could generate an individual perception of the object, that is not an image of some thing, but a solicitation to viewers to stay with it. The works seeks to generate affection (in Deleuze’s sense) while intervening in the flow of flux–image in the contemporary time.

Stuart E. Madnick, project supervisor. / Includes bibliographical references.

Despite the fact that photographs come into being as material objects imprinted with light reflected off the subject in front of the camera, and therefore possess a decidedly physical connection to their referent, the materiality of photographs tends to be overlooked in favour of apprehending them as primarily visual signs independent of their physical support. This practice-led research project under the title Taking Photographs Beyond the Visual: Paper as a Material Signifier in Photographic Indexicality explores the status of photographs as physical traces. In an attempt to find ways in which remote natural locations could be expressed more fully than it is possible by means of purely visual representation, papermaking and image-formation are combined in a single process executed entirely on-site. This working method was developed during the course of the project through artist residencies in Switzerland and a thorough research of traditional papermaking that included visits to numerous European paper mills. The making of each work involves an absurdly laborious and time-consuming process of hiking to an alpine location, making paper on-site from local plants and - using only the inherent light-sensitivity of plant substances - exposing it for many days in a camera built there partly from found natural materials. The resulting photographic objects function as pure indices in the semiotician Charles Sanders Peirce’s understanding of the term – as traces that point to their causes without necessarily revealing anything about the nature of the latter. They are artefacts testifying primarily through their presence, rather than through pictorial representation, to the exposure having taken place. Such process of signification requires the viewer’s active, haptic and imaginative response. The work proposes a way of photographically representing place as elemental - that is, existing outside the human schema of production, consumption and meaning – instead of through such cultural constructs as ‘landscape’ or ‘the scenic’.

I have used practice as method to investigate the creative potential of portable projectors, and theoretical approaches to reflect on: 1. the perception of the environment and its textures, 2. the sense of place-making and being while in motion, 3. the portability and collective mediation of the environment, and 4. the collaborative process of participation. These four themes emerged from the four video walks I developed during the research: The Surface Inside (2011), I-Walk (2012), Walk-itch (2013), and (wh)ere land (2014). To delve into the philosophical nuances and practical outcomes, I have paired the four video walks with the four themes. This research approach resembles the design process, where practice develops in the action of reflection (Schon, 1983). The thesis and portfolio are the result of an iterative practice-reflection process which is based on the thread metaphor. The experience of being and walking in the environment is proprioceptive (J. J. Gibson, 1986) and can only be partially conveyed through audiovisual records. People experience the complex texture of the environment in motion (i.e. accretion of surfaces). While moving, they thread their own paths into the environment (Ingold, 2007) and establish links with the environment, technology and others. As they move, people experience the texturality of the surfaces they encounter. Video records captured with visual apparatuses (Flusser, 2000) are a fraction of the points of observation a person may have adopted while walking in and experiencing the environment. These records are likely to be created with PEDs, shared in digital environments and accessed on digital screens. When these records are experienced on digital screens, the texture of the environment is reduced to a flat surface. PEDs, with their digital screens, are carried around everyday and enable people to communicate with others, to collect and share audiovisual material, and to experience hybrid environments where tangible and digital realms converge (Coyne, 2010). Audiovisuals can be accessed anywhere and are no longer dependent on the architectures that hosted them in the past. Yet, PEDs may also isolate people from their immediate surroundings and favour introspective engagement with audiovisual content, digital others and digital environments (Turkle, 2011). The size of PEDs limits the number of people that can engage with the content at only one time. Pocketsize devices tend to be used individually, and their audiovisual content played through digital screens and headphones which foster cocoon-like engagement. Through the four video walks, I investigate how portable projectors may be used to challenge this inward looking mode of experiencing audiovisuals on flat digital screens, and to devise participatory events where people thread their paths in the environment, and project and engage with audiovisuals together. In the video walks, I invite people to move with projections and explore mediated public environments. Instead of sitting in front of fixed projections or looking at digital screens, people experience and share visuals while walking and projecting them in the environment. Portable projectors are starting to be embedded in mobile phones and other portable electronic devices (PEDs), and this presents new challenges and opportunities to creative practitioners. Thus, I study the affordances of portable projectors and develop artworks where participants walk, project visuals and explore textures in the environment collectively.

Fundamental aspects of biologically-inspired regulatory mechanisms are considered in a robotics context, using artificial neural-network control systems . Regulatory mechanisms are used to control expression of genes, adaptation of form and behavior in organisms. Traditional neural network control architectures assume networks of neurons are fixed and are interconnected by wires. However, these architectures tend to be specified by a designer and are faced with several limitations that reduce scalability and tractability for tasks with larger search spaces. Traditional methods used to overcome these limitations with fixed network topologies are to provide more supervision by a designer. More supervision as shown does not guarantee improvement during training particularly when making incorrect assumptions for little known task domains. Biological organisms often do not require such external intervention (more supervision) and have self-organized through adaptation. Artificial neural tissues (ANT) addresses limitations with current neural-network architectures by modeling both wired interactions between neurons and wireless interactions through use of chemical diffusion fields. An evolutionary (Darwinian) selection process is used to ‘breed’ ANT controllers for a task at hand and the framework facilitates emergence of creative solutions since only a system goal function and a generic set of basis behaviours need be defined. Regulatory mechanisms are formed dynamically within ANT through superpositioning of chemical diffusion fields from multiple sources and are used to select neuronal groups. Regulation drives competition and cooperation among neuronal groups and results in areas of specialization forming within the tissue. These regulatory mechanisms are also shown to increase tractability without requiring more supervision using a new statistical theory developed to predict performance characteristics of fixed network topologies. Simulations also confirm the significance of regulatory mechanisms in solving certain tasks found intractable for fixed network topologies. The framework also shows general improvement in training performance against existing fixed-topology neural network controllers for several robotic and control tasks. ANT controllers evolved in a low-fidelity simulation environment have been demonstrated for a number of tasks on hardware using groups of mobile robots and have given insight into self-organizing system. Evidence of sparse activity and use of decentralized, distributed functionality within ANT controller solutions are found consistent with observations from neurobiology.

Fundamental aspects of biologically-inspired regulatory mechanisms are considered in a robotics context, using artificial neural-network control systems . Regulatory mechanisms are used to control expression of genes, adaptation of form and behavior in organisms. Traditional neural network control architectures assume networks of neurons are fixed and are interconnected by wires. However, these architectures tend to be specified by a designer and are faced with several limitations that reduce scalability and tractability for tasks with larger search spaces. Traditional methods used to overcome these limitations with fixed network topologies are to provide more supervision by a designer. More supervision as shown does not guarantee improvement during training particularly when making incorrect assumptions for little known task domains. Biological organisms often do not require such external intervention (more supervision) and have self-organized through adaptation. Artificial neural tissues (ANT) addresses limitations with current neural-network architectures by modeling both wired interactions between neurons and wireless interactions through use of chemical diffusion fields. An evolutionary (Darwinian) selection process is used to ‘breed’ ANT controllers for a task at hand and the framework facilitates emergence of creative solutions since only a system goal function and a generic set of basis behaviours need be defined. Regulatory mechanisms are formed dynamically within ANT through superpositioning of chemical diffusion fields from multiple sources and are used to select neuronal groups. Regulation drives competition and cooperation among neuronal groups and results in areas of specialization forming within the tissue. These regulatory mechanisms are also shown to increase tractability without requiring more supervision using a new statistical theory developed to predict performance characteristics of fixed network topologies. Simulations also confirm the significance of regulatory mechanisms in solving certain tasks found intractable for fixed network topologies. The framework also shows general improvement in training performance against existing fixed-topology neural network controllers for several robotic and control tasks. ANT controllers evolved in a low-fidelity simulation environment have been demonstrated for a number of tasks on hardware using groups of mobile robots and have given insight into self-organizing system. Evidence of sparse activity and use of decentralized, distributed functionality within ANT controller solutions are found consistent with observations from neurobiology.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A urgÃncia desta pesquisa parte de uma investigaÃÃo artÃstica acerca da aÃÃo de permanecer na cidade de Fortaleza. A partir do contexto da extrema desigualdade social e das inÃmeras chacinas que ocorreram entre os anos de 2015 e 2016, perÃodo de realizaÃÃo da pesquisa, desenvolvo exercÃcios de permanÃncia no litoral da cidade, mais especificamente a partir dos espigÃes - muros de contenÃÃo construÃdos entre o mar e a cidade. Ao desenvolver tais exercÃcios, cujas reflexÃes estÃo tambÃm presentes nesse texto, concentro-me em conjugar o verbo/procedimento de permanecer. NÃo se trata de um exercÃcio alheio ao corpo. Ao tratar a permanÃncia como um gesto de resistir no espaÃo, que nÃo se fixa, percebo o delicado equilÃbrio entre ir e ficar. / The urgency of this research is based on an artistic investigation about the action of staying in the city of Fortaleza. In the context of the extreme social inequality and the numerous slaughterings that took place between the years 2015 and 2016, during the period of the research, I develop permanence exercises on the coast of the city, more specifically the retaining walls built between the sea and the city. In developing these exercises, whose reflections are also present in this text, I concentrate on conjugating the verb / procedure of permanence. It is not an out of body exercise. In treating permanence as a gesture of resistance in space, which does not settle, I perceive the delicate balance between going and staying.