A DISSERTATION PRESENTED TO THE HIGHER DEGREES COMMITTEE OF PENINSULA TECHNIKON IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE MASTER OF TECHNOLOGY: GRAPHIC DESIGN, 2004 / Inkjet printers have evolved in recent years to the extent that many are capable of making prints of a quality closely approximating traditional colour photographs. These printers cost a fraction of the capital outlay needed to equip a traditional colour darkroom and have brought high quality colour printing within the reach of a broad spectrum of users. As they are capable of printing on a wide range of materials and print surfaces prints from inkjet printers are also in demand by fine artists and art collectors. Commercial printmakers, artists, photographers, and amateurs printing in their homes or offices use these printers. The convenience, ease, and quality of inkjet printing have made it a popular additional and alternative photographic printing technique. However, manufacturers seldom publish data regarding the expected life of the printer output. With traditional colour photographs end users expect some fading to take place with time and can normally have another print made from the original negative. Digital images rely on storage on compact disk or computer hard drive with potential long-term retrieval problems, and it is vital that important images be output in print form on the most stable materials. This study arose from the author’s concern about the archival qualities of photographs in general. In order to enable end users to make more informed choices about the most suitable printing medium, this study explored two aspects concerning traditional photographs and inkjet prints, namely cost and image permanence. The comparative costs were found by means of a questionnaire survey conducted among a representative sample of printmakers. The limits of image permanence were determined by subjecting sample prints to a high-intensity light source to accelerate the process of image fading over time to the point where the print becomes unacceptable. The investigation showed that inkjet prints are more expensive than traditional photographs, and that inkjet prints made with pigment inks can last twice as long as traditional photographs. Different inkjet papers were found to have no significant effect on the life of the print during the period of this test. Inkjet prints made with dyes were shown to have a short life before fading unacceptably. The study led to the recommendation that for the longest print life a print to be displayed should be printed on an inkjet paper with pigment inks.

The task of determining which of many available color-difference formulae is appropriate for any give application can be arduous. Researchers and practitioners alike are faced with the selection of one formula which best describes perceived color differences under conditions in which the equation is to be employed. The idea that one equation can be formulated which takes into consideration all factors affecting perceived color difference has yet to be realized, and perhaps never will. As a result, an “every man for himself” approach has developed. Yet, color-difference equations are continually being applied to conditions without empirical evidence to support their use. While the 1976 CIELAB Color Difference Equation has been applied for some time in the photographic industry, its use in describing the perceived magnitude of large color differences in photographic prints has not been validated. Furthermore, a good deal of research has suggested that the CIELAB equation is not applicable under numerous conditions of color-difference assessment. Nonetheless, the results of the study reported here support the use of CIELAB over four other formulae (CIELUV, CMC (1:1), Richter, and Yu’v’) for describing perceived color differences in photographic prints. CIELAB produced moderate correlations for both experienced and non-experienced color judges over the range of color space examined. The results of this work support the use of the 1976 CIELAB Color Difference Equation for describing the perceived magnitude of moderate and large color differences in photographic prints. / Master of Science

We have introduced a geometry which is invariant to certain forms of burning and dodging photographic prints. We then used this geometry to create invariant measurements which represent information which would not change given different photographic printing processes. / The presented algorithm used properties of best-fit planes to represent a photograph. There are many other possibilities for measurements which would fit this framework. Further, the representation of photographs presented in this thesis could be combined with existing computer vision algorithms for such tasks as object recognition within photographs for which we do not know the development process.

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Made available in DSpace on 2014-06-11T19:22:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-27Bitstream added on 2014-06-13T18:49:18Z : No. of bitstreams: 1 coelho_al_me_ia.pdf: 3987728 bytes, checksum: 372a0c136117bae0a6fd9f8d3426685a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esta pesquisa tem como propósito investigar uma técnica de impressão fotográfica chamada antotipia. Praticamente esquecida pela história da fotografia, a antotipia se vale de fotossensibilidade dos pigmentos vegetais contidos nas flores para produzir impressões que se caracterizam por sua qualidade monocromática, baixa gama de contraste e efemeridade. A partir da perspectiva historiográfica de Walter Benjamin, testemunhos como manuais de fotografia e artigos científicos oriundos do século XIX são observados, criticados e analisados historicamente. Os procedimentos artesanais envolvidos na prática da antotipia são então testados e organizados numa metodologia prática, de modo a resgatar este processo de impressão para o contexto contemporâneo. Os conteúdos estudados ao longo da pesquisa são então interpretados e traduzidos visualmente na série de fotografias impressas em antotipia chamado Atlas Oblivione / This research has the purpose of investigate a photographic printing technique called anthotype. Pratically olivious to the History of Photography the anthotype uses the photosensitivity of vegetable dyes found in flowers to produce prints notable by its monochromatic quality, low range of contrast and ephemerality. Based on the historiographical perspective formulated by Walter Benjamin, evidences as photographic manuals and scientific papers from the nineteenth century are historically observed, criticized and analyzed. The handmade proceidures involved on the anthotype are tested and organized in a practical metodology in order to rescue this photographic printing process from oblivion to the contamporaneity. The subjects studied throughout the research are then interpreted visually in the series of anthotype photographs named Atlas Oblivione

Orientador: Luiz Guimarães Monforte / Banca: Marco Francisco Buti / Banca: Pelópidas Cypriano / Resumo: Esta pesquisa tem como propósito investigar uma técnica de impressão fotográfica chamada antotipia. Praticamente esquecida pela história da fotografia, a antotipia se vale de fotossensibilidade dos pigmentos vegetais contidos nas flores para produzir impressões que se caracterizam por sua qualidade monocromática, baixa gama de contraste e efemeridade. A partir da perspectiva historiográfica de Walter Benjamin, testemunhos como manuais de fotografia e artigos científicos oriundos do século XIX são observados, criticados e analisados historicamente. Os procedimentos artesanais envolvidos na prática da antotipia são então testados e organizados numa metodologia prática, de modo a resgatar este processo de impressão para o contexto contemporâneo. Os conteúdos estudados ao longo da pesquisa são então interpretados e traduzidos visualmente na série de fotografias impressas em antotipia chamado Atlas Oblivione / Abstract: This research has the purpose of investigate a photographic printing technique called anthotype. Pratically olivious to the History of Photography the anthotype uses the photosensitivity of vegetable dyes found in flowers to produce prints notable by its monochromatic quality, low range of contrast and ephemerality. Based on the historiographical perspective formulated by Walter Benjamin, evidences as photographic manuals and scientific papers from the nineteenth century are historically observed, criticized and analyzed. The handmade proceidures involved on the anthotype are tested and organized in a practical metodology in order to rescue this photographic printing process from oblivion to the contamporaneity. The subjects studied throughout the research are then interpreted visually in the series of anthotype photographs named Atlas Oblivione / Mestre

The objectives of this research were (1) to develop scales of preferred image sharpness for thermal dye transfer prints and (2) to relate these scales to an objective measurement of image quality. Interval scales were developed using two different indirect scaling techniques, paired comparison and rank ordering, for three groups of participants (novice photographers, advanced amateur photographers, and Kodak image quality experts). Differences between scales developed through the separate scaling procedures were minor, suggesting that either procedure would produce a reliable and valid interval scale. Given the time required to perform the method of paired comparisons, the method of rank ordering would likely be the preferred procedure. The results from multiple range tests of the interval scales found that higher levels of image sharpening (filter levels 1.5x to 2.5x) were generally preferred. However, for some conditions, particularly the portrait, lower levels of sharpening were generally preferred. While it appears that the preferred level of image sharpness may be somewhat dependent upon scene content, participants always preferred a small amount of sharpening to none at all. For all conditions examined, stimuli that received no sharpening were the least preferred. In relating interval scales to an objective measure of image quality, scale values developed from within a level of addressability were highly correlated with values of modified MTFA for all participant groups. These correlations show that a strong relationship exists between preferred levels of image sharpness and increasing levels of luminance modulation for edges in thermal prints. However, values of modified MTFA were not well correlated with interval scale values developed from experts participants for the between levels of addressability portion of the experiment. Values of MTFA were considered modified due to limits that were imposed on the bounds of integration. These results suggest that the preferences of experts may not represent those of the average consumer for desired levels of thermal print sharpness. / Ph. D.

The problem with which this comparative investigation is concerned is the application of a photographically derived image to glass. The image used originated from an ordinary thirty-five-millimeter color slide. This slide, through photographic darkroom manipulation, was translated into thirty individually different, black and white films of four-by-five-inch size. Selected films were then enlarged onto eleven-by-fourteen-inch, Kodalith film. These enlarged films were contact exposed to Ulano's Blue Poly-3, a presensitized silkscreen photofilm. This in turn was adhered to twelve double X silk which was tautly stretched in a wooden frame.