Innovative Techniques for Digitizing and Restoring Deteriorated Historical Documents

Recent large-scale document digitization initiatives have created new modes of access to modern library collections with the development of new hardware and software technologies. Most commonly, these digitization projects focus on accurately scanning bound texts, some reaching an efficiency of more than one million volumes per year. While vast digital collections are changing the way users access texts, current scanning paradigms can not handle many non-standard materials. Documentation forms such as manuscripts, scrolls, codices, deteriorated film, epigraphy, and rock art all hold a wealth of human knowledge in physical forms not accessible by standard book scanning technologies. This great omission motivates the development of new technology, presented by this thesis, that is not-only effective with deteriorated bound works, damaged manuscripts, and disintegrating photonegatives but also easily utilized by non-technical staff. First, a novel point light source calibration technique is presented that can be performed by library staff. Then, a photometric correction technique which uses known illumination and surface properties to remove shading distortions in deteriorated document images can be automatically applied. To complete the restoration process, a geometric correction is applied. Also unique to this work is the development of an image-based uncalibrated document scanner that utilizes the transmissivity of document substrates. This scanner extracts intrinsic document color information from one or both sides of a document. Simultaneously, the document shape is estimated to obtain distortion information. Lastly, this thesis provides a restoration framework for damaged photographic negatives that corrects photometric and geometric distortions. Current restoration techniques for the discussed form of negatives require physical manipulation to the photograph. The novel acquisition and restoration system presented here provides the first known solution to digitize and restore deteriorated photographic negatives without damaging the original negative in any way. This thesis work develops new methods of document scanning and restoration suitable for wide-scale deployment. By creating easy to access technologies, library staff can implement their own scanning initiatives and large-scale scanning projects can expand their current document-sets

Portraits, Preservation & Pedigrees: An Introduction to Photographic Portraiture, Photographs as a Means of Genealogical Research, and a Preservation Case Study of the Howard D. Beach Studio Collection of Glass Plate Negatives

Photography is an established art form that combines the knowledge of chemistry, light, and optics to render an image. Initially, the image is captured on a flat surface coated with emulsion and combined with an exposure to sunlight or another illuminating source. Today, images are captured by digital methods. Artistically, the photograph may reveal sceneries of landscapes, of treasured belongings and of people, as they are seen to the human eye. Photographic portraiture is the oldest style of photography next to landscape imagery, due to commercial photographers setting up studios and experimenting with photography’s many cameras, plates, and emulsions. In the late nineteenth century, the dry gelatin glass plate negative emerged to replace its predecessors, and created a booming business in photographic material manufacturers. Today, museums, archives and libraries in the United States are using current technologies and knowledge of the dry gelatin glass plate negative to preserve them for long-term accessibility and research use. Of the many research uses, genealogists use these plates to identify ancestors and build upon a family history. This thesis will provide a brief history of photography, an insight into photographic portraiture, and steps to preserve dry gelatin glass plate negatives. It will also involve a background of genealogical research with the use of photographs. Lastly, this paper will contain a case study conducted by the author of the preservation and genealogical research of the Howard D. Beach Studio Photography Collection of Glass Plate Negatives, as provided by The Buffalo History Museum in Buffalo, New York

Method and Apparatus for 3D Imaging a Workpiece

To obtain a three-dimensional virtual reconstruction of a workpiece the workpiece is positioned on a display screen between the display screen and at least one imager wherein the imager acquires multiple images of the workpiece while (a) multiple light stripes are displayed and swept in a first directional orientation across the display screen, (b) multiple light stripes are displayed and swept in at least one second directional orientation across the display screen, and (c) multiple images for each position of the multiple light stripes at different exposure times are captured. From the multiple images, a difference caused by the workpiece in a width and a profile of the multiple light stripes is determined. That difference is used to calculate a depth value (z) of the workpiece at each imager pixel position (x, y). The calculated depth value is used to reconstruct a surface shape of the workpiece. In embodiments, the described transmittance light capture analyses are supplemented with reflectance light capture analyses

From Grain to Pixel

Film is in a state of rapid change, with the transition from analog to digital profoundly affecting not just filmmaking and distribution, but also the theoretical conceptualization of the medium film and the practice of film archiving. New forms of digital archives are being developed that make use of participatory media to provide a more open form of access than any traditional archive has offered before. Film archives are thus faced with new questions and challenges. From Grain to Pixel attempts to bridge the fields of film archiving and academic research, by addressing the discourse on film ontology and analysing how it affects the role of film archives. Fossati proposes a new theoretization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists.Het bewegende beeld bevindt zich in een overgangsperiode waarin analoge (fotochemische) film geleidelijk vervangen wordt door digitale film. Deze overgang heeft niet alleen diepgaande invloed op filmproductie en -distributie, maar ook op de manier van archiveren van film en de theoretische conceptualisering van dit medium. Van digitale archieven worden steeds nieuwe vormen ontwikkeld. Deze archieven - digitale filmdatabases en YouTube bijvoorbeeld - maken gebruik van media die participatie van vele gebruikers mogelijk maken en worden zo toegankelijker dan ooit. Ondertussen is er nog onvoldoende dialoog tussen archivarissen en filmwetenschappers. From Grain to Pixel slaat een brug tussen archiveringspraktijken en wetenschappelijk onderzoek dat gebaseerd is op relevante debatten in film- en nieuwe mediastudies. Fossati stelt een nieuwe theorie op voor het archiveren en restaureren van film. Dit biedt mogelijkheden voor een hernieuwde dialoog tussen archivarissen en wetenschappers

From Grain to Pixel

"In From Grain to Pixel , Giovanna Fossati analyzes the transition from analog to digital film and its profound effects on filmmaking and film archiving. Reflecting on the theoretical conceptualization of the medium itself, Fossati poses significant questions about the status of physical film and the practice of its archival preservation, restoration and presentation. From Grain to Pixel attempts to bridge the fields of film archiving and academic research by addressing the discourse on film's ontology and analyzing how different interpretations of what film is affect the role and practices of film archives. Ultimately, Fossati proposes a novel theorization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists. Almost a decade after its first publication, this updated edition covers the latest developments in the field. Besides a new general introduction, a new conclusion and extensive updates to each chapter, a novel theoretical framework and a new case study have been added. Giovanna Fossati is chief curator at EYE Filmmuseum and professor of film heritage and digital film culture at the University of Amsterdam.

Ângelo de Sousa’s photographic and film collection: strategies for the preservation of colour slide-based artworks

The Portuguese artist Ângelo de Sousa (1938-2011) produced noteworthy work in photography and experimental film. However, a lack of in-depth studies focusing on the use of these media by the artist is acknowledged. Thus, his work has been studied, particularly through unpublished documentation found in the artist’s house and in public archives, bringing new insights into his production. Despite the delay in the artistic context felt in Portugal in the post-modern period, Ângelo de Sousa produce photographic and film work perfectly in line with that of other international artists. The slide-based artwork Slides de Cavalete (1978-1979), constructed with the additive synthesis of colours, stands out as an example of the inventiveness achieved by the artist with these media. The production process behind Slides de Cavalete has been studied and reproduced, allowing for a thorough understanding of the work and contributing to the definition of its significance. The photographs and films have been gathered together in his house. Since typologies, quantities and condition of the materials were unknown, a survey was carried out to enhance knowledge of the collection and to define preservation priorities. Accordingly, 35 mm chromogenic reversal films (slides), used to produce almost all his photographic colour work, was highlighted as the set in highest risk due to colour change detected in one third of these materials. Thereby, slide-based artworks by Ângelo de Sousa were studied in further detail. The display options undertaken by the artist during his lifetime have been investigated, in order to guide the decision-making process regarding the exhibition and preservation of his slide-based artworks. Slides de Cavalete was selected as a case study, and the history of its exhibition was assessed by searching for documentation and interviewing people. Thus, it is understood that the work was first presented projected on a canvas over an easel, in 1979. Since the artist’s death, the work has been presented without this setup, and recently, as a digital projection. An exhibition was conducted at FCT NOVA, to test the variability of the work displayed with a digital and a slide projector. Based on a questionnaire, a clear preference for the slide projection was acknowledged. Thus, guidelines for the exhibition of Slides de Cavalete are defined, following its first presentation. Considering that chromogenic reversal films are highly susceptible to colour change and that there is still much to know about these materials, their molecular characterization and degradation has been studied. Different pathways to characterize chromogenic dyes are suggested based on chromatographic and spectroscopic techniques. Additionally, a methodology to accurately monitor colour change in these materials has been defined, based on samples artificially aged at different temperatures (50, 60, 70 and 80˚C) and relative humidity (40% and 60%). The samples were assessed using spectrophotometry with optical fibre probes in the ultraviolet-visible range. From the spectral data, intensity maximums, CIE L*a*b* coordinates and the total colour variation (ΔE*) have been determined. Optical microscopy and digitization have also proven useful for degradation assessment on these materials

From Grain to Pixel

Film is in a state of rapid change, with the transition from analog to digital profoundly affecting not just filmmaking and distribution, but also the theoretical conceptualization of the medium film and the practice of film archiving. New forms of digital archives are being developed that make use of participatory media to provide a more open form of access than any traditional archive has offered before. Film archives are thus faced with new questions and challenges. From Grain to Pixel attempts to bridge the fields of film archiving and academic research, by addressing the discourse on film ontology and analysing how it affects the role of film archives. Fossati proposes a new theoretization of film archival practice as the starting point for a renewed dialogue between film scholars and film archivists

A contribution for the preservation of cellulose esters black and white negatives

Cellulose esters film-based negatives are known for their autocatalytic and irreversible decay. Over time, the ephemeral nature of these negatives became one of the most challenging issues for manufacturers, photographers, scientists, conservators, and overall caretakers that strive to foresee the decay of those composite materials and to develop preservation solutions. The aim of this study is to introduce an analytical methodology that can inform the conservator not only about the nature of the film base but also about its condition in a non-invasive way. For this purpose, three hundred and sixty-one cellulose nitrate and cellulose acetate film-based negatives (1930s-1950s) from Portuguese institutions were selected. The selection of the cases studies relied on three main criteria: historical framework of the collection, film characteristics (type of support, format, producers/brands) and preservation condition. The selected negatives are representative of European and North American producers. The objects were studied using infrared and Raman microspectroscopies (μ-FTIR and μ-Raman), pH and hardness measurements, and Near infrared spectroscopy. μ-FTIR analysis allowed to identify three types of film supports: cellulose nitrate, cellulose acetate and cellulose acetate butyrate. Based on the μ-FTIR analysis a correlation between molecular identification of the film base and notch codes was accomplished. For the set of negatives with cellulose acetate butyrate support no significant molecular changes were obtained, indicating that this type of negatives is considerably stable. Concerning cellulose nitrate and acetate-based negatives, μ-FTIR allowed to assess very different preservation conditions, ranging from Very Good to Severely degraded. A careful observation of the results obtained for cellulose nitrate-based negatives allowed concluding that negatives with spectral changes associated with severe degradation may have different degradation pathways according to thickness. Concerning cellulose acetate-based negatives, similar results were obtained. Moreover, the FTIR results enabled to identify a degradation trend associated with a film typology characterized by ‘U’ notch code and blue and brown anti-halation dyes. Different plasticizers, namely camphor, phosphates and phthalates, were also identified by μ-FTIR and μ-Raman analysis. pH and hardness measurements supported the spectral results obtained. It was confirmed that the de-esterification and chain-scission may be detected by their decrease. To confirm the chemical behaviour of cellulose nitrate-based negatives, an artificial ageing experiment (80⁰C, 90% RH) was carried out, followed by the same analytical methodology. The results obtained for samples artificially aged support the findings obtained from the study of historical films. These findings contribute for a review of the preservation strategies currently used, establishing a novel and non-invasive methodology which could provide accurate tools for the identification of early degradation stages of negatives with cellulose nitrate and cellulose acetate supports. By examining by μ-EDXRF and SEM-EDS the image layer of a set of cellulose nitrate negatives presenting colours, it was possible to identify the chemical elements present and correlate them with possible intensification and reduction treatments used to improve image density and contribute for the knowledge of Portuguese photographers working methods

Identifying challenges in the conservation of South African photography based on three case studies

Mini Dissertation (MSocSci (Tangible Heritage Conservation))--University of Pretoria, 2022.Photographs have a visual tie to human memory in that they are used to capture moments of significance, and give a visual illustration of how something looks at that moment and time. Visual representation, in the way it is connected to human memory, has become an important tool in historical and heritage studies. Photographs allow for senses of the past to be seen and experienced, which is one of the primary reasons why pictures are safeguarded. This dissertation focuses on the ways in which photographic conservation gives special attention to the preservation of photographs. I will review the conservation and archival practices that the following three collections use to care for their photographs: the Duggan-Cronin collection at the McGregor Museum in Kimberley, the Bensusan Museum collection at Museum Africa in Johannesburg, and the Rashid Lombard collection, which is being donated to the University of the Western Cape. Each of these three collections tell a South African heritage story as seen through photography from 1866 to present. They cover different aspects that form an integral part of the history of South Africa, including the colonial era, the era of The Union of South Africa, apartheid and the post-apartheid era. It is important to understand the technological and social evolution of photography because how an objectis made, the materials it ismade of, and how it is used in research and exhibition, all influence its longevity, preservation, and deterioration. To complement observations in the three case studies, a survey was circulated through the South African Museums Association requesting participation. The survey allowed for a broader view to be formulated as to how different Museums in South Africa care for their photographs and to guide the formulation of context appropriate guidelines for handling, storage, exhibition and albeit briefly, digitization. Keywords: South African photographic collections Preventative conservation Photographic conservation Collections care and managementTangible Heritage ConservationMSocSci (Tangible Heritage Conservation)Unrestricte