375 research outputs found

    Simulation of an electrophotographic halftone reproduction

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    The robustness of three digital halftoning techniques are simulated for a hypothetical electrophotographic laser printer subjected to dynamic environmental conditions over a copy run of one thousand images. Mathematical electrophotographic models have primarily concentrated on solid area reproductions under time-invariant conditions. The models used in this study predict the behavior of complex image distributions at various stages in the electrophotographic process. The system model is divided into seven subsystems: Halftoning, Laser Exposure, Photoconductor Discharge, Toner Development, Transfer, Fusing, and Image Display. Spread functions associated with laser spot intensity, charge migration, and toner transfer and fusing are used to predict the electrophotographic system response for continuous and halftone reproduction. Many digital halftoning techniques have been developed for converting from continuous-tone to binary (halftone) images. The general objective of halftoning is to approximate the intermediate gray levels of continuous tone images with a binary (black-and-white) imaging system. Three major halftoning techniques currently used are Ordered-Dither, Cluster-Dot, and Error Diffusion. These halftoning algorithms are included in the simulation model. Simulation in electrophotography can be used to better understand the relationship between electrophotographic parameters and image quality, and to observe the effects of time-variant degradation on electrophotographic parameters and materials. Simulation programs, written in FORTRAN and SLAM (Simulation Language Alternative Modeling), have been developed to investigate the effects of system degradation on halftone image quality. The programs have been designed for continuous simulation to characterize the behavior or condition of the electrophotographic system. The simulation language provides the necessary algorithms for obtaining values for the variables described by the time-variant equations, maintaining a history of values during the simulation run, and reporting statistical information on time-dependent variables. Electrophotographic variables associated with laser intensity, initial photoconductor surface voltage, and residual voltage are degraded over a simulated run of one thousand copies. These results are employed to predict the degraded electrophotographic system response and to investigate the behavior of the various halftone techniques under dynamic system conditions. Two techniques have been applied to characterize halftone image quality: Tone Reproduction Curves are used to characterize and record the tone reproduction capability of an electrophotographic system over a simulated copy run. Density measurements are collected and statistical inferences drawn using SLAM. Typically the sharpness of an image is characterized by a system modulation transfer function (MTF). The mathematical models used to describe the subsystem transforms of an electrophotographic system involve non-linear functions. One means for predicting this non-linear system response is to use a Chirp function as the input to the model and then to compare the reproduced modulation to that of the original. Since the imaging system is non-linear, the system response cannot be described by an MTF, but rather an Input Response Function. This function was used to characterize the robustness of halftone patterns at various frequencies. Simulated images were also generated throughout the simulation run and used to evaluate image sharpness and resolution. The data, generated from each of the electrophotographic simulation models, clearly indicates that image stability and image sharpness is not influenced by dot orientation, but rather by the type of halftoning operation used. Error-Diffusion is significantly more variable than Clustered-Dot and Dispersed-Dot at low to mid densities. However, Error-Diffusion is significantly less variable than the ordered dither patterns at high densities. Also, images generated from Error-Diffusion are sharper than those generated using Clustered-Dot and Dispersed-Dot techniques, but the resolution capability of each of the techniques remained the same and degraded equally for each simulation run

    The diversity of digital print technologies used in the creation of high quality Fine Art

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    The Centre for Fine Print Research in Bristol UK undertakes research into print technologies from the traditional 19th Century to the latest digital capture and print. Outcomes of this research are often realised in collaborative projects with well-known artists. The breadth of technologies used in the creation of printed digital art is huge, and often mixes analogue and digital techniques. At the CFPR we print artwork using digital photographic technologies that range from, fired enamel on metal for largescale public art projects, continuous tone photo-ceramic relief panels, digital moulds for glass artists. On-glaze ceramic print, Digital photogravure, flexographic print both intaglio and relief, Helio-relief, collotype and Woodburytype, as well as large-scale digital inkjet for Blue chip artists such as Richard Hamilton. In order to understand and quantify colour and surface print quality differences between each process, colourmetric measurement is available alongside microphotography to support and back up the subjective analytical data that is collected during a project. Examples from this data will be used to illustrate the differences between digital print techniques and explain why the artist has chosen a particular print technique. In order to fully explain the breadth of technologies available this paper will also demonstrate the work other studios from Europe and the USA that develop projects using digital technologies to print artists work

    Digital Color Imaging

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    This paper surveys current technology and research in the area of digital color imaging. In order to establish the background and lay down terminology, fundamental concepts of color perception and measurement are first presented us-ing vector-space notation and terminology. Present-day color recording and reproduction systems are reviewed along with the common mathematical models used for representing these devices. Algorithms for processing color images for display and communication are surveyed, and a forecast of research trends is attempted. An extensive bibliography is provided

    Digital imaging technology assessment: Digital document storage project

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    An ongoing technical assessment and requirements definition project is examining the potential role of digital imaging technology at NASA's STI facility. The focus is on the basic components of imaging technology in today's marketplace as well as the components anticipated in the near future. Presented is a requirement specification for a prototype project, an initial examination of current image processing at the STI facility, and an initial summary of image processing projects at other sites. Operational imaging systems incorporate scanners, optical storage, high resolution monitors, processing nodes, magnetic storage, jukeboxes, specialized boards, optical character recognition gear, pixel addressable printers, communications, and complex software processes

    The development of methods for the reproduction in continuous tone of digitally printed colour artworks

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    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

    Journalistic Practice and the Cultural Valuation of New Media: Topicality, Objectivity, Network

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    Around the turn of the twenty-first century, American journalism is undergoing an existential crisis provoked by the emergence of digital and networked communication. As the economic model of producing journalism is undergoing significant changes, this study argues that the crisis of journalism is primarily a cultural crisis of valuation. Because the practices that traditionally defined the exclusivity of journalism as a form of public communication have been transposed to the online and digital environment through social media and blogs, such practices no longer value journalism in the same terms like in the age of mass media. The key to understanding the cultural crisis of journalism in the present, this study argues, is to revise the traditional narrative and its associated terminologies of the institutionalization of journalism. Journalism is thus defined as a structure of public communication, which needs to be enacted by producers and audiences alike to become socially meaningful. The consequence of seeing journalism as a structure sustained through social practices is that it allows to see the relation between audiences and their journalistic media as constitutive for the social function of new media in journalism. Through the analytically central dimension of practice, the study presents key moments in the history of modern journalism, where the meaning of new media was negotiated. These moments include the emergence of topical news media oriented toward a mass market (the penny press in the 1830s) and the definition of a schema of objectivity which valued journalistic practice in professional and scientific terms around the turn of the twentieth century in analogy to photographic media. In each phase, material, cognitive and social practices helped to define the value of a given new medium for journalism. Through the schemas of topicality and objectivity, journalistic practice institutionalized a privileged structure of public communication. The legacy of defining these schemas is then regarded as the central reason for the cultural crisis of journalistic practice in the present, as practices have been transposed and re-valued to sustain either forms of alternative journalism (as peer-production) or forms of self-communication in network media like blogs. Neither the form nor the technology of the blog alone can explain this differential social relevance but only the different ways in which social practices integrated and value new media. The study synthesizes an interdisciplinary array of concepts from cultural studies, sociology and journalism studies on subjects such as public communication, interaction, news production and cultural innovation. The theoretical framework of practice theories is then applied to an extensive body of primary and secondary source material, in order to retrace the cultural valuation of new media in a historically-comparative perspective. The study offers a theoretical and empirical contribution to the analysis of cultural innovation, which can be adopted to other cultural forms and media

    FAMILY AND OTHER RELATIONS A thesis examining the extent to which family relationships shape the relations of art.

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    Access to the full-text thesis is no longer available at the author's request, due to 3rd party copyright restrictions. Access removed on 28.11.2016 by CS (TIS).This thesis is sited in contemporary issues concerning gender and identity in relation to the arts. It aims to examine the nature of the family and the extent to which relationships and identities in the family might be analogous to the relations of fine art; these include relations between the artist and the artwork, between what is defined as 'art' and what is not, between the artwork and the viewer. It also touches on some of the other, innumerable relationships encountered in the arts: relations of materials form, feeling, thinking and making. The thesis contains a discussion of the nature of family identities and relationships based on my own experiences in the mid-twentieth century and today. Families are at first divided into two main types, nonnative and ethicaL These types represent the difference between ideal or stereotypical family relations and the way families actually live in practice. Analogies are made between normative families and traditional modes of defining art and ethical family relations and ethical notions of art. In the last chapter I suggest that relations that are core and normative are linked to marginal relations through ethical links made by liminal figures that pass between them. Although issues of identity, patriarchy and binary difference appear in theoretical writings on art criticism and practice, there appears to be little contemporary debate in these issues in relation to the family and its relationships. The thesis begins to map out the terrain of such a field of enquiry

    Greenham Common’s archival webs: towards a virtual feminist museum

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    The Women’s Peace Camp at Greenham Common (1981-2000) was a women-only camp originally established in protest against nuclear proliferation and the Cold War ideology of deterrence that fuelled the arms race. The peace camp initiated a series of performative protest actions on and off site, including teddy bears’ picnics, and mock weddings of protesters to nuclear warheads by Shirley Cameron and Evelyn Silver. The perimeter fence of the airbase was soon transformed into a permanent if informal gallery of protest, hosting a wealth of visual and material interventions which were widely documented. The Greenham women used a range of print media to communicate amongst themselves and with the world beyond the camp, including newsletters, posters, postcards, and leaflets, most of which were richly illustrated with original artwork. From an art historical perspective, this material teems with visual iconographies drawing upon ancient myths and symbols already mobilised in women’s movements since the 1960s. In addition to the reclamation of witches and witches’ circles, spider webs were successfully exploited in craftivist performance and evoked in drawing, as a motif of solidarity, connectivity, and soft strength. Mother-and-child iconographies were revisited and reconfigured, in evocation of the familiar maternalism of women’s peace movements yet at the same time sabotaging the visual supports of social reproduction. Many artworks were created at or in reference to Greenham, often by artists with direct experience of the camp, including textile and installation work by Janis Jefferies, Margaret Harrison’s multiple iterations of the reconstructed perimeter fence, Tina Keane’s films of protest and reverie, and Thalia Campbell’s textile collages and banners. I suggest that Greenham, viewed through the lens of feminist intergenerational transmission, exemplifies Griselda Pollock’s formulation of the virtual feminist museum. Mobilising Aby Warburg’s Nachleben (afterlife/survival by metamorphosis), the virtual feminist museum untethers artefacts, images, and practices from their historical contexts and sets them in motion, tracing their travels, re-occurrences and transformations across time and space. For Pollock, virtuality is not opposed to actuality but vibrates with the possibility of imminent realisation. I propose a curatorial experiment that activates the virtual feminist museum of Greenham Common and feminist anti-nuclear activism more broadly, while also teasing out a repertory of anti-war, anti-patriarchal ‘pathos formulae’ or affectively charged tropes, from care rituals to failing phalluses, and including the playful reclamation of the perimeter fence from its intended function. The highly visual format of the ‘Animating the Archive’ series of British Art Studies helps test Warburg’s quasi-method of tracing iconographic correspondences across disparate spaces, times, and registers, through the dispersed and diverse visual archive of Greenham Common

    The adoption and impact of computer integrated prepress systems in the printing and publishing industries of Kuwait

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    This research is aimed at developing a comprehensive picture of the implications of digital technology in the graphic arts industries in Kuwait. The purpose of the study is twofold: (1) to explore the meaning of the outcomes of recent technological change processes for the traditional prepress occupations in Kuwait; and, (2) to examine the impact of technology on Arabic layout and design. The study is based on the assumption that technological change is a chain of interactions among the sociological, cultural, political and economic variables. The prepress area in Kuwait has its own cultural, social, economic, and political structure. When a new technology is introduced it is absorbed and shaped by the existing structure. Based on such a dialectical conceptualisation, four major levels of analysis can be distinguished in this study: (1) technological change in the graphic arts industries; (2) the typographic evolution of the Arabic script; (3) the workers themselves as individuals and occupational collectives; and, (4) technology's impact on Arabic publication design. The methodological approach selected for this study can be defined as a dialectical, interpretive exploration. Given the historical perspective and the multiple levels of analysis, this approach calls for a variety of data gathering methods. Both qualitative and quantitative data were sought. A combination of document analysis, participant observation and interviewing allow to link the historical and current events with individual and collective actions, perceptions and interpretations of reality. The findings presented in this study contradicts the belief that the widespread adoption of new production processes is coincidental with continuous advances in scientific knowledge which provide the basis for the development of new technologies. Instead, the changes have been hindered by the lack of untrained personnel, the Arabic software incompatibility, and the lack of informed decisions to successfully implement the technology. Without any doubt, the new technology has influenced Arabic calligraphy, but this does not mean the decay of Arabic calligraphy as an art. As this study shows, the challenge is not to the art, but to the artist

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